A Quick Start Guide to Open Source Marketing Software (2026)

What Is Open Source Marketing Automation Software?

Open source marketing automation software consists of platforms with publicly available source code that organizations can install, modify, and deploy without restrictive licensing agreements. Unlike proprietary solutions from vendors like HubSpot or Marketo, these tools grant users complete access to the underlying codebase, enabling customization at every level. For IT managers evaluating deployment options, this means you control the entire technology stack rather than relying on vendor APIs and feature roadmaps.

Marketing automation through open source platforms handles repetitive marketing tasks including email campaign execution, lead scoring, customer journey mapping, and behavioral tracking. The software typically runs on your own servers or cloud infrastructure, eliminating dependency on third-party hosting and providing direct access to customer data without intermediaries.

The distinction matters significantly for organizations with specific compliance requirements or custom integration needs. While proprietary platforms charge monthly per-user or contact-volume fees, open source alternatives often charge only for hosting infrastructure and optional support services. A mid-market company managing 500,000 contacts might pay $2,000 to $5,000 monthly for HubSpot or Marketo, whereas self-hosted Mautic or Dittofeed typically costs $500 to $1,500 monthly for equivalent infrastructure.

Open source marketing software operates through modular architectures where each component (email engine, contact database, campaign builder, analytics) functions independently yet integrates seamlessly. This modular approach allows organizations to enable only needed features, reducing server resource consumption and complexity. Community contributions continuously expand marketplace integrations, meaning new connectors to third-party tools appear regularly without waiting for vendor development cycles.

Core Advantages for IT Managers and Business Leaders

Cost Structure and Total Cost of Ownership

The financial case for open source marketing automation centers on three components: software licensing, infrastructure hosting, and implementation support. Most open source marketing platforms carry zero licensing costs, contrasting sharply with proprietary competitors charging $1,200 to $12,000 annually per user seat. For organizations with 10 to 50 marketing team members, eliminating per-user licensing generates substantial savings.

Infrastructure costs depend entirely on deployment model. Cloud-hosted options through providers like AWS, DigitalOcean, or Linode typically cost $100 to $500 monthly for small deployments and $500 to $3,000 monthly for enterprise-scale installations with high traffic and large contact databases. On-premises deployment transfers infrastructure responsibility entirely to your IT team, eliminating ongoing hosting fees but requiring dedicated server resources and bandwidth.

Implementation and customization represent the largest hidden cost. While software itself costs nothing, deploying a marketing automation platform requires initial configuration (3 to 8 weeks for mid-market implementations), staff training (40 to 80 hours), and ongoing optimization. Many organizations budget $15,000 to $50,000 for first-year implementation when using professional services, though this cost applies equally to proprietary and open source solutions.

Multi-year ROI analysis demonstrates significant advantages. A company with 15 marketing employees might pay $180,000 annually for HubSpot ($12,000 per user) plus $2,000 monthly for additional contacts and features. The equivalent Mautic deployment costs roughly $45,000 in initial setup plus $600 monthly for infrastructure, totaling $52,200 in year one and $7,200 in subsequent years. Over five years, this represents $88,800 in savings while delivering equivalent functionality.

Data Ownership and Privacy Compliance

Regulatory environments increasingly favor organizations maintaining direct data custody. GDPR, CCPA, and emerging privacy frameworks grant customers data rights that require vendor transparency and data portability. Open source platforms hosted on your infrastructure provide complete audit trails, direct deletion capabilities, and compliance evidence that proprietary vendors cannot guarantee.

Matomo exemplifies privacy-first architecture by design. This analytics platform stores all visitor data within your infrastructure rather than sending it to external servers, eliminating the need for complex data processing agreements (DPAs). Organizations using Matomo demonstrate GDPR compliance more easily since data never leaves their control. Contrast this with Google Analytics, where tracking data flows to Google’s distributed systems and cannot be deleted with customer certainty.

Direct data access enables organizations to implement proprietary business logic around customer information. Some industries require data retention policies, encryption standards, or access controls exceeding cloud vendor capabilities. Open source platforms allow your engineering team to implement these controls directly in the application layer rather than negotiating custom feature requests with product teams.

Vendor independence becomes critical during contract negotiations. Proprietary platform customers face significant switching costs when attempting to migrate to competitors, incentivizing vendors to increase pricing over contract renewal cycles. Open source platforms eliminate this negotiating disadvantage. If your vendor increases support costs beyond acceptable levels, you can maintain the platform internally or switch providers without data extraction challenges.

Customization and Integration Depth

Organizations with non-standard marketing workflows often encounter feature gaps in proprietary platforms. Customization requests typically require feature requests, product roadmap prioritization, and multi-release delays before implementation. Open source alternatives allow your development team to implement required functionality immediately through direct code modification.

Integration patterns differ fundamentally between proprietary and open source approaches. Proprietary platforms offer REST APIs and webhooks as integration mechanisms, limiting customization to what vendors explicitly support. Open source platforms allow direct database access, internal API modifications, and event-driven customization through middleware. A marketing operation requiring real-time synchronization between the marketing automation platform and a legacy ERP system can implement direct database triggers with open source tools, whereas proprietary solutions restrict integrations to documented API endpoints.

Strapi, a headless CMS solution, demonstrates customization depth through its content type and API generation capabilities. Rather than adapting your workflow to platform constraints, you define custom content models matching your exact business requirements, and Strapi automatically generates matching REST and GraphQL APIs. This inversion of control enables marketing teams to structure data exactly as their business processes demand rather than conforming to vendor assumptions.

Multi-channel integration becomes simpler with open source architectures. A healthcare organization requiring separate email sequences for patient communication, provider outreach, and staff coordination can implement custom fields and campaign logic that proprietary platforms reserve for enterprise plans costing $25,000 to $100,000 annually. Open source platforms support these requirements at base licensing costs.

Comparing Open Source Marketing Automation Platforms

Platform	Primary Function	Hosting Model	Base Cost	Email Contacts	Key Strengths	Best For
Mautic	Marketing Automation	Self-hosted	Free	Unlimited	Lead scoring, behavioral tracking, drag-and-drop campaigns	Mid-market B2B companies
Matomo	Web Analytics	Self-hosted	Free	N/A	GDPR compliance, complete data ownership, visitor heatmaps	Privacy-conscious organizations
Listmonk	Email Marketing	Self-hosted	Free	Unlimited	High performance, lightweight, multiple SMTP support	Newsletter publishers, content creators
Odoo CRM	CRM + Marketing	Self-hosted or Cloud	Free	Unlimited	Integrated with ERP, financial, project modules	Organizations needing unified business platform
Dittofeed	Marketing Automation	Self-hosted	Free	Unlimited	Customer segmentation, data quality tools, scalability	Enterprise organizations processing high-volume campaigns
ERPNext	ERP + CRM	Self-hosted	Free	Unlimited	Integrated financial, HR, inventory modules	Small to mid-market organizations needing unified systems
FluentCRM	CRM + Email	Self-hosted	Free (WordPress plugin)	Unlimited	WordPress native, ease of use, basic automation	WordPress-based businesses, small teams
Ghost	Publishing + Newsletter	Self-hosted	Free	Unlimited	Content-first design, membership features, built-in email	Content creators, newsletter publishers

Mautic: Comprehensive Marketing Automation Platform

Mautic represents the most mature open source marketing automation solution, actively developed since 2014 with over 6,000 GitHub stars and contributions from 200+ developers. The platform provides complete marketing automation capabilities including email campaign builders, landing page designers, dynamic content personalization, and advanced lead scoring algorithms comparable to enterprise-grade proprietary solutions.

Core functionality spans customer journey mapping through multi-step automation workflows, behavioral tracking that records website interactions and email engagement, and dynamic segment creation based on 100+ attributes. These capabilities enable marketing teams to implement sophisticated nurturing sequences that respond to customer actions in real-time. A B2B SaaS company might create a workflow where enterprise prospects receive different email sequences than SMB prospects based on company size data captured during signup.

Mautic deployments typically begin at $500 to $1,000 monthly for AWS hosting supporting 500,000 contacts, scaling to $2,000 to $5,000 monthly for 5,000,000 contacts with high email volume. Professional services for implementation average $10,000 to $25,000. Commercial support through the Mautic community or specialized agencies costs $500 to $2,000 monthly depending on service level and customization requirements.

Integration capabilities include 100+ pre-built connectors through the Mautic marketplace, REST API access for custom integrations, and webhook support for event-driven workflows. Connectors exist for Salesforce, HubSpot data migration, Shopify, WordPress, Zapier, and most standard business applications. Unlike proprietary platforms limiting API request rates, self-hosted Mautic instances support unlimited API calls limited only by server resources.

Matomo: Privacy-First Web Analytics

Matomo addresses the critical analytics gap for organizations requiring complete data control and GDPR compliance. This web analytics platform provides visitor tracking, behavior analysis, and conversion measurement capabilities while maintaining data entirely within your infrastructure. Organizations can deploy Matomo on-premises and ensure visitor data never leaves their servers, solving the privacy concerns associated with Google Analytics data transfer to external services.

Features include custom event tracking, heatmap generation showing exactly where users click and scroll, form analytics identifying abandonment points, and cohort analysis comparing user segments. Real-time visitor tracking allows marketing teams to monitor campaign performance as visitors arrive, and custom dashboards enable non-technical stakeholders to view KPIs without accessing raw data.

Matomo pricing follows a hybrid model: free self-hosted version with unlimited sites and visitors, or cloud-hosted plans starting at $19 monthly for small sites and reaching $599 monthly for enterprise deployments. Large organizations often choose self-hosted Matomo to minimize recurring costs, with infrastructure expenses typically $200 to $800 monthly for analytics processing 100 million visits annually.

Integration with marketing automation platforms occurs through custom event APIs. Mautic and other platforms can fire custom events to Matomo when visitors complete specific actions (email click, landing page signup, purchase), creating unified behavioral tracking across owned properties. This integration capability addresses the “single customer view” requirement that most marketing organizations need but proprietary analytics platforms restrict to enterprise contracts.

Listmonk: Lightweight Email Campaign Manager

Listmonk focuses specifically on email campaign delivery with minimal resource consumption, making it ideal for organizations prioritizing simplicity over comprehensive automation. This platform excels at newsletter distribution, segmented email campaigns, and subscriber management without the complexity of full marketing automation suites.

Core capabilities include subscriber list management with custom fields and metadata, templated campaign building with both drag-and-drop and HTML editors, scheduling with timezone support, and SMTP relay configuration supporting unlimited providers. Performance optimization allows Listmonk to send 100,000 emails per hour on modest hardware, and the platform requires only 50 MB disk space and 50 MB RAM for typical installations.

Deployment costs remain minimal. Docker containerization enables deployment on any hosting provider within $5 to $20 monthly on shared hosting or $30 to $100 monthly on dedicated resources. No licensing fees apply regardless of subscriber count or email volume, though organizations managing millions of subscribers typically allocate $200 to $500 monthly for sufficient server resources.

Integration patterns center on API-driven subscriber management and campaign triggering. Applications can subscribe users through REST API calls, and Listmonk webhooks can notify external systems when subscribers click emails or mark campaigns as spam. This approach suits organizations with existing subscriber databases in Postgres or MySQL who need simple email delivery without replacing their entire data infrastructure.

Odoo CRM: Integrated Business Platform

Odoo represents a different category: a unified business platform where CRM and marketing functionality integrate with financial accounting, inventory management, human resources, and project management. Organizations needing to consolidate multiple systems benefit from Odoo’s integrated approach, whereas those requiring a standalone marketing tool may find unnecessary complexity.

Marketing module capabilities include lead and opportunity management, email template creation, mass email campaigns, and pipeline visualization. The platform tracks all customer interactions within a unified database, eliminating data silos between sales, marketing, and service teams. Unlike standalone marketing automation tools requiring integration to access CRM data, Odoo provides immediate access to customer records within the same system.

Deployment options span self-hosted Odoo installations managed entirely by your IT team, or Odoo Cloud hosting starting at $60 monthly for basic deployments and reaching several thousand dollars monthly for enterprise configurations. Self-hosted deployments typically cost $200 to $1,500 monthly for hosting supporting 50 to 500 users. Implementation complexity increases compared to standalone marketing tools, with typical deployments requiring 8 to 16 weeks and $25,000 to $75,000 professional services investment.

The unified database approach creates powerful reporting and automation. A customer acquisition campaign tracked entirely in Odoo can automatically generate invoices, schedule follow-up tasks for account managers, and trigger shipping workflows when opportunities convert to sales. This level of integration requires custom development in standalone marketing automation platforms integrated with separate ERP systems.

Dittofeed: Enterprise Segmentation and Automation

Dittofeed specializes in customer segmentation and sophisticated targeting, addressing organizations processing millions of customer records requiring complex behavioral logic. The platform emphasizes data quality, segment reliability, and campaign performance optimization through advanced audience definition.

Core features include segment builder supporting multi-condition targeting (e.g., users in geographic region X who purchased product Y within last 30 days and scored above Z on engagement metric), journey orchestration coordinating multi-channel campaigns across email, SMS, push notifications, and webhooks, and A/B testing frameworks for messaging optimization. The platform handles customer profile enrichment and historical data access enabling retroactive campaign analysis.

Dittofeed deployments typically begin at $1,000 to $2,000 monthly for infrastructure supporting 10 million customer records, scaling to $5,000 to $10,000 monthly for 100 million records with complex segmentation. Unlike contact-based pricing, Dittofeed charges based on segment complexity and query frequency, aligning costs with actual platform usage.

Performance optimization becomes critical with Dittofeed’s scale. The platform implements query caching and materialized views to accelerate segment evaluation, ensuring multi-million-customer audiences can execute within seconds rather than hours. Organizations operating customer data platforms (CDPs) often select Dittofeed as the activation layer, syncing customer segments from CDP systems and executing campaigns through Dittofeed’s orchestration engine.

Essential Integration and Deployment Considerations

API Integration Patterns and Limitations

Open source marketing platforms support REST APIs and webhook mechanisms for external system integration, though depth and performance characteristics vary significantly. Mautic provides extensive API coverage for contacts, segments, campaigns, forms, and custom fields, enabling applications to read and write marketing data directly. REST API rate limits depend entirely on your server resources, meaning unlimited API access depends solely on infrastructure capacity rather than vendor subscription tier.

Webhook capabilities enable event-driven integrations where external systems trigger actions within the marketing platform or vice versa. A customer support system might send webhooks to Mautic when customers open support tickets, automatically updating customer profiles and triggering relevant email sequences. These event-driven patterns reduce data synchronization delays compared to batch-based integration approaches.

Integration complexity increases when connecting to legacy systems lacking modern APIs. Organizations maintaining older ERP or CRM systems may require custom development to extract customer data, transform it to Mautic-compatible formats, and load it through APIs. Budget 40 to 80 hours of custom development for moderately complex integrations involving data transformation logic.

Third-party integration marketplaces expand available connectors. Zapier provides connections between open source marketing platforms and 3,000+ business applications without requiring direct API integration. A company using Slack for team communication could configure Zapier to send Slack notifications whenever high-value leads engage with campaigns, bridging the gap between marketing platform and team communication tools.

Hosting and Infrastructure Requirements

Deployment architecture decisions significantly impact platform performance and operational overhead. Shared hosting environments starting at $10 to $30 monthly support very small deployments (under 10,000 contacts, minimal email volume), but lack the resources for production marketing operations. Most organizations deploy on cloud platforms providing on-demand resource scaling.

AWS deployments for Mautic typically use the following architecture: t3.medium EC2 instance ($30 to $40 monthly) for application servers, RDS PostgreSQL database ($50 to $100 monthly for small installations), ElastiCache Redis ($20 to $50 monthly for session and cache management), and S3 storage ($5 to $20 monthly). Total monthly infrastructure cost reaches $105 to $210 for small production deployments, scaling to $500 to $1,500 monthly as contact volume and email throughput increase.

DigitalOcean and Linode offer cost-effective alternatives to AWS for organizations preferring simpler pricing. DigitalOcean Droplets provide comparable functionality at $12 to $100 monthly depending on CPU, memory, and storage allocation. Managed databases and load balancing services integrate more simply than AWS equivalents, reducing operational complexity for teams without significant cloud infrastructure experience.

Kubernetes orchestration becomes important for organizations processing 50+ million contacts or handling 1 million+ emails daily. Platform deployments on managed Kubernetes services (AWS EKS, DigitalOcean Kubernetes, Google Kubernetes Engine) provide automatic scaling responding to traffic spikes and email volume fluctuations. These deployments typically cost $1,000 to $5,000 monthly but eliminate the need for predictive capacity planning and manual scaling decisions.

Security, Compliance, and Operational Requirements

Self-hosted marketing platforms place responsibility for security patching, backup procedures, and disaster recovery entirely on your organization. Unlike proprietary SaaS platforms where vendors handle infrastructure maintenance, open source deployments require IT team involvement for ongoing operational management.

Security patching requires monitoring project repositories for vulnerability announcements and implementing updates within your deployment schedule. Most open source projects release security patches within 24 to 48 hours of disclosure, but your organization must deploy these patches promptly. Establish a process for testing patches in development/staging environments before production deployment, adding 5 to 10 business days to patch cycles.

Backup and disaster recovery responsibilities shift to IT teams. Define backup frequency (daily backups represent standard practice) and retention periods (30 to 90 days minimum). Test recovery procedures quarterly to ensure backups function when needed. Database encryption, SSL/TLS configuration, API authentication, and access control logging all require implementation and ongoing monitoring by your IT team.

Compliance auditing becomes simpler with self-hosted platforms. HIPAA, PCI DSS, SOC 2, and other compliance frameworks require organization control over data handling, encryption, and access. Proprietary platforms often limit compliance configuration and evidence generation to audit-specific features. Self-hosted platforms allow your team to implement controls exceeding standard requirements and generate comprehensive audit trails demonstrating compliance.

User access management differs from proprietary platforms. Open source marketing platforms typically provide role-based access control (RBAC) allowing assignment of permissions to marketing users without granting infrastructure access. However, LDAP, OAuth, and SAML integration for single sign-on (SSO) varies by platform and may require additional configuration or custom development.

Selecting the Right Open Source Marketing Platform: A Decision Framework

Defining Organizational Requirements

Platform selection begins with honest assessment of specific capabilities your marketing operation requires. Common requirement categories include: email marketing volume (contacts per month, emails per month), campaign complexity (single sends vs. multi-step workflows), integration depth (number of external systems requiring data synchronization), compliance scope (GDPR, HIPAA, PCI DSS, industry-specific requirements), and budget constraints.

Volume requirements dramatically impact platform selection. Organizations sending fewer than 50,000 emails monthly find Listmonk or Ghost adequate for newsletter distribution. Mid-market companies executing sophisticated lead nurturing campaigns across 500,000 to 5,000,000 contacts require Mautic or Odoo. Enterprise organizations managing complex customer segments and multi-channel orchestration across 50+ million records need Dittofeed or custom CDP implementations.

Integration requirements determine architectural complexity. Simple integrations requiring periodic contact file imports or basic webhook notifications suit standalone platforms like Mautic. Organizations requiring real-time bidirectional synchronization with ERP, financial, and service systems benefit from Odoo’s unified database or custom integration architectures combining multiple specialized platforms.

Compliance requirements affect security implementation and audit burden. Healthcare organizations requiring HIPAA compliance need database encryption, audit logging, and access controls exceeding standard open source platform capabilities. Public sector organizations needing FedRAMP certification essentially eliminate open source options due to certification cost complexity. Most commercial organizations requiring only GDPR compliance find open source platforms fully capable of compliance implementation.

Team capability assessment determines realistic implementation scope. Organizations with experienced developers can manage complex Mautic or Odoo deployments and customization. Marketing-driven organizations without technical infrastructure teams should prioritize simplicity over feature breadth, potentially selecting Listmonk or Ghost rather than comprehensive platforms requiring ongoing technical maintenance.

Evaluating Feature Parity and Extension Options

Create detailed feature matrices comparing required functionality against available open source options. Essential categories typically include: email template editing (visual builders vs. HTML-only), landing page builders, list segmentation capabilities (basic vs. advanced behavioral targeting), automation workflows (conditional logic, multi-step sequences, time-based triggers), and reporting (basic analytics vs. custom dashboards).

Extension and customization capabilities determine long-term platform value. Mautic’s marketplace provides 100+ pre-built plugins expanding functionality without custom development. ERPNext and Odoo communities contribute thousands of modules adding specialized features. Evaluate whether required functionality exists as contributed extensions or whether custom development becomes necessary.

Community maturity indicates sustainability and available support. Platforms with 5,000+ GitHub stars, 200+ active contributors, and active community forums typically provide sufficient sustainability for five-year deployments. Smaller projects with fewer than 500 stars and declining activity indicate higher risk of maintenance burden shifting to your organization.

Performance characteristics matter for email volume. Listmonk achieves 100,000+ emails per hour on modest hardware, whereas Mautic’s performance depends heavily on configuration and server resources. Evaluate platform benchmarks against your email volume requirements, adding 50% headroom for growth and spike handling.

Total Cost Projections and Budget Planning

Develop three-year total cost of ownership (TCO) spreadsheets comparing open source and proprietary options for your organization. Include: software licensing (typically $0 for open source vs. $1,200 to $12,000 per user annually for proprietary), infrastructure hosting ($200 to $3,000 monthly for open source vs. included in SaaS pricing for proprietary), implementation services ($15,000 to $50,000 one-time), ongoing support ($500 to $2,000 monthly optional for open source vs. included for proprietary), and staff time for operations and customization.

Common cost comparisons: five-person marketing team using HubSpot typically costs $60,000 to $120,000 annually in licensing plus $24,000 in annual contact management. Equivalent Mautic deployment costs $600 to $1,200 monthly in infrastructure plus $10,000 to $25,000 one-time implementation, totaling $17,200 to $39,400 in year one and $7,200 to $14,400 in subsequent years. Over five years, Mautic represents $68,400 to $116,400 in costs versus $300,000 to $600,000 for HubSpot.

Budget surprises often emerge from underestimated professional services. Initial platform deployment typically costs 40 to 80 consulting hours at $150 to $250 per hour, totaling $6,000 to $20,000. Custom integrations requiring development add $5,000 to $25,000. Ongoing support averaging 4 to 10 hours monthly at equivalent rates adds $600 to $2,500 monthly. Plan conservatively assuming 20% higher implementation costs than initial estimates.

Hidden costs in proprietary platforms often involve data export and migration when switching vendors. Open source platforms allow complete data export in standard formats without switching penalties, whereas proprietary vendors may charge data extraction fees and provide limited export options. Factor this vendor lock-in risk into long-term cost calculations.

Comparison of Self-Hosted Versus Managed Cloud Deployment Models

Self-Hosted Deployment Architecture and Responsibilities

Self-hosted open source platforms run entirely on infrastructure you provision and manage, typically on AWS, DigitalOcean, Linode, or private data centers. This approach eliminates vendor dependency and provides maximum control over data, infrastructure, and customization, but transfers all operational responsibility to your IT organization.

Operational responsibilities include: infrastructure provisioning (selecting and configuring servers), database administration (backups, performance tuning, failover configuration), security management (firewall rules, SSL certificates, intrusion detection), software updates (testing and deploying patches), disaster recovery (maintaining backups and documenting recovery procedures), and performance monitoring (tracking resource utilization and scaling as needed).

Docker containerization significantly reduces self-hosted operational burden. Docker images for Mautic, Matomo, and other platforms encapsulate all software dependencies, enabling consistent deployments across environments and simplifying scaling. Docker Compose configurations define multi-container applications combining application servers, databases, cache layers, and reverse proxies, enabling single-command deployment of complex architectures.

Kubernetes orchestration further simplifies operations for organizations processing high email volume or managing multiple applications. Managed Kubernetes services on AWS, Google Cloud, or DigitalOcean handle infrastructure provisioning and security updates while you manage application deployments and scaling policies. Organizations processing 50+ million customer records or sending millions of emails daily should evaluate Kubernetes deployment to handle traffic variability without manual intervention.

Managed Cloud and Vendor-Hosted Options

Some open source projects offer managed cloud hosting as alternative to self-hosted deployments. Mautic Cloud provides hosted Mautic instances starting at $99 monthly for small deployments and reaching several thousand monthly for enterprise configurations. Odoo Cloud offers similar managed hosting. These options eliminate operational responsibility while preserving most open source advantages like data ownership and customization.

Managed hosting represents a middle ground between proprietary SaaS and self-hosted open source. You avoid infrastructure management but retain ability to export data and customize functionality. Pricing typically ranges 30 to 50% lower than equivalent proprietary SaaS offerings while providing comparable ease of use.

Limitations of managed hosting include: reduced customization capabilities (infrastructure modifications may require vendor approval), limited integration options (custom code execution restricted for security), and potential vendor lock-in risk (switching involves data export rather than system migration). Evaluate managed hosting when operational overhead exceeds cost savings or when your organization lacks infrastructure expertise.

Frequently Asked Questions About Open Source Marketing Automation