Open source focus
Open Source Alternatives to Lettermail
60 open source Email Productivity options similar to Lettermail, ranked by named competitors first, sector overlap, and our 0-100 AI-readiness score. Each profile notes license and self-hosting where we have it.
CultivateaiSales AutomationOpen source
Manus AI75Agentic AISingapore, Singapore$150.0MOpen source
NemoClaw75Artificial IntelligenceOpen source · Self-hostable
Hightouch70Customer Data PlatformSan Francisco, United States$322.0MOpen source
Viktor62Artificial IntelligenceWarsaw, Poland$64.7MOpen source
Agency58Agentic AISan Francisco, United States$20.0MOpen source
timeOS56PersonalSan Francisco, United States$3.3MOpen source
M Magical54Artificial IntelligenceSan Francisco, United StatesOpen source
giniX54Generative AITel Aviv, IsraelOpen source
Relevance AI53Agentic AITel Aviv, Israel$12.0MOpen source
Emergence AI48Agentic AISan Francisco, United StatesOpen source
Taskade46SpaceTechNew York, United States$1.0MOpen source
Outlit45Agentic AI$500KOpen source
Nex AI45Agentic AISan Francisco, United StatesOpen source
Stably AI45Agentic AITel Aviv, IsraelOpen source
Behrings40Agentic AISan Francisco, United StatesOpen source
- RERefold AI39Customer Service AutomationLondon, United Kingdom$6.5M
Open source
Zynk36Agentic AILondon, United Kingdom$110.0MOpen source
Joulix AI Technologies35AI Tools & AppsSan Francisco, Israel$2.3MOpen source
Skyridge Systems34Agentic AISan Francisco, United StatesOpen source
- Arkano21Agentic AITel Aviv, Israel
Open source
Upsonic19Developer ToolsLondon, United KingdomOpen source · Self-hostable
Etherwaves AI14Conversational AIOpen source
Ssbs14Agentic AIOpen source
- ProcureraaProcurement Software
Open source
VoltexaAgentic AITel Aviv, IsraelOpen source
StranahanAgentic AIOpen source
GlobalsolutantsEnterprise SoftwareOpen source
BidfitSales EnablementTel Aviv, IsraelOpen source
KedmahConversational AITel Aviv, IsraelOpen source
Open and AsyncAgentic AISan Francisco, United StatesOpen source
DemirtasAgentic AITel Aviv, IsraelOpen source
TheclearpointAgentic AIOpen source
DivisionlabAgentic AITel Aviv, IsraelOpen source
LayeerAgentic AITel Aviv, IsraelOpen source
LetscConversational AIOpen source
IntelligentstaffingsystemsHR TechLondon, United KingdomOpen source
MowjazAgentic AITel Aviv, IsraelOpen source
DomulisConversational AILondon, United KingdomOpen source
RitonaAI AgentTel Aviv, IsraelOpen source
ZycoreAgentic AIOpen source
AixeedAgentic AITel Aviv, IsraelOpen source
HunexAgentic AIOpen source
SimbulosAgentic AISan Francisco, United StatesOpen source
GetmunimGovTechTel Aviv, IsraelOpen source
SanadgroupAgentic AITel Aviv, IsraelOpen source
TauworkAgentic AIOpen source
Aegis XWorkflow AutomationTel Aviv, IsraelOpen source
AidlesAgentic AITel Aviv, IsraelOpen source
Kairos6AI AgentOpen source
BranchflowAgentic AISan Francisco, United StatesOpen source
ApartechConversational AISan Francisco, United StatesOpen source
Coworker.aiHR TechOpen source
MorphizAgentic AITel Aviv, IsraelOpen source
SapmindsEnterprise SoftwareLondon, United KingdomOpen source
ZovarusAgentic AIOpen source
ProvendSales AutomationOpen source
- AdamczykAgentic AISan Francisco, United States$1.0M
Open source
- InbrowserAgentic AI
Open source
AutaniaAgentic AISan Francisco, United StatesOpen source
| Company | Sector | License | HQ | Funding | Score |
|---|---|---|---|---|---|
| Cultivateai | Sales Automation | Open source | — | — | — |
| Manus AI | Agentic AI | Open source | Singapore, Singapore | $150.0M | 75 |
| NemoClaw | Artificial Intelligence | Open source · Self-hostable | — | — | 75 |
| Hightouch | Customer Data Platform | Open source | San Francisco, United States | $322.0M | 70 |
| Viktor | Artificial Intelligence | Open source | Warsaw, Poland | $64.7M | 62 |
| Agency | Agentic AI | Open source | San Francisco, United States | $20.0M | 58 |
| timeOS | Personal | Open source | San Francisco, United States | $3.3M | 56 |
| M Magical | Artificial Intelligence | Open source | San Francisco, United States | — | 54 |
| giniX | Generative AI | Open source | Tel Aviv, Israel | — | 54 |
| Relevance AI | Agentic AI | Open source | Tel Aviv, Israel | $12.0M | 53 |
| Emergence AI | Agentic AI | Open source | San Francisco, United States | — | 48 |
| Taskade | SpaceTech | Open source | New York, United States | $1.0M | 46 |
| Outlit | Agentic AI | Open source | — | $500K | 45 |
| Nex AI | Agentic AI | Open source | San Francisco, United States | — | 45 |
| Stably AI | Agentic AI | Open source | Tel Aviv, Israel | — | 45 |
| Behrings | Agentic AI | Open source | San Francisco, United States | — | 40 |
| RERefold AI | Customer Service Automation | Open source | London, United Kingdom | $6.5M | 39 |
| Zynk | Agentic AI | Open source | London, United Kingdom | $110.0M | 36 |
| Joulix AI Technologies | AI Tools & Apps | Open source | San Francisco, Israel | $2.3M | 35 |
| Skyridge Systems | Agentic AI | Open source | San Francisco, United States | — | 34 |
| Agentic AI | Open source | Tel Aviv, Israel | — | 21 | |
| Upsonic | Developer Tools | Open source · Self-hostable | London, United Kingdom | — | 19 |
| Etherwaves AI | Conversational AI | Open source | — | — | 14 |
| Ssbs | Agentic AI | Open source | — | — | 14 |
| Procurement Software | Open source | — | — | — | |
| Voltexa | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Stranahan | Agentic AI | Open source | — | — | — |
| Globalsolutants | Enterprise Software | Open source | — | — | — |
| Bidfit | Sales Enablement | Open source | Tel Aviv, Israel | — | — |
| Kedmah | Conversational AI | Open source | Tel Aviv, Israel | — | — |
| Open and Async | Agentic AI | Open source | San Francisco, United States | — | — |
| Demirtas | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Theclearpoint | Agentic AI | Open source | — | — | — |
| Divisionlab | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Layeer | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Letsc | Conversational AI | Open source | — | — | — |
| Intelligentstaffingsystems | HR Tech | Open source | London, United Kingdom | — | — |
| Mowjaz | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Domulis | Conversational AI | Open source | London, United Kingdom | — | — |
| Ritona | AI Agent | Open source | Tel Aviv, Israel | — | — |
| Zycore | Agentic AI | Open source | — | — | — |
| Aixeed | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Hunex | Agentic AI | Open source | — | — | — |
| Simbulos | Agentic AI | Open source | San Francisco, United States | — | — |
| Getmunim | GovTech | Open source | Tel Aviv, Israel | — | — |
| Sanadgroup | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Tauwork | Agentic AI | Open source | — | — | — |
| Aegis X | Workflow Automation | Open source | Tel Aviv, Israel | — | — |
| Aidles | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Kairos6 | AI Agent | Open source | — | — | — |
| Branchflow | Agentic AI | Open source | San Francisco, United States | — | — |
| Apartech | Conversational AI | Open source | San Francisco, United States | — | — |
| Coworker.ai | HR Tech | Open source | — | — | — |
| Morphiz | Agentic AI | Open source | Tel Aviv, Israel | — | — |
| Sapminds | Enterprise Software | Open source | London, United Kingdom | — | — |
| Zovarus | Agentic AI | Open source | — | — | — |
| Provend | Sales Automation | Open source | — | — | — |
| Agentic AI | Open source | San Francisco, United States | $1.0M | — | |
| Agentic AI | Open source | — | — | — | |
| Autania | Agentic AI | Open source | San Francisco, United States | — | — |