Open source Salesforce alternatives

Every project in the catalog is MIT, Apache or BSD licensed. 0 projects explicitly describe themselves as a Salesforce alternative; 15 more are in the category where Salesforce is a typical product.

Open source projects in the same category: Email & CRM / Mailchimp Alternatives

Category-level information: these projects are the same kind of software as Salesforce; they have not claimed to be a one-to-one replacement.

DO

docker-mailserver · Email & CRM / Mailchimp Alternatives

STARS19.7K
FORKS2.1K
COMMITS—
CONTRIBUTORS361
VERSIONv9.1.0
UPDATED4 days ago
Email ServerSMTPIMAPDockerMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You can easily install and manage your own mail server using configuration files.
  • You can filter email traffic with integrated anti-spam and anti-virus tools.
  • You can configure user access with LDAP or OAuth2 authentication methods.
User reviews
  • • NeutralHacker News

    Docker-mailserver: Production-ready mail server running inside a container

    “A vibrant MIT-licensed project that currently is maintained by Georg Lauterbach and has a most recent commit from 2 weeks ago, 17.2k stars, 82 open issues (2,158 closed), 11 pull requests, and 329 contributors. > docker-mailserver, or DMS for short, is a production-ready…”

NO

nodemailer · Email & CRM / Mailchimp Alternatives

STARS17.7K
FORKS1.4K
COMMITS—
CONTRIBUTORS164
VERSIONv9.0.3
UPDATED2 days ago
EmailNode.jsSMTPDKIMMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • Send an email from your Node.js application through the SMTP protocol.
  • You configure email sending with the ES module or CommonJS structure in different working environments.
  • By managing TLS and security settings, you set up email connections.
User reviews
  • • NeutralHacker News

    Why I replaced MIT with copyleft license for Nodemailer

    “I understand the switch to copyleft, but the EU's own website explicitly lists GPL licenses as incompatible, in the matrix on this page: Dual-licensing under the EUPL and GPL, with the option to choose either, would be helpful. Otherwise Nodemailer is incompatible with the…”

  • • NeutralHacker News

    Why I replaced MIT with copyleft license for Nodemailer

    “Speaking from my corner of a large organisation, this is pretty spot on. $100-300 is "no brainer". LDAP/AD, OAuth is major plus. Support SLAs tiers are also something we would look for, even in Open Source. We don't use Nodemailer, but we might now that I know about it. I'll see…”

PO

postalserver · Email & CRM / Mailchimp Alternatives

STARS16.9K
FORKS1.3K
COMMITS657
CONTRIBUTORS51
VERSION3.3.7
UPDATEDyesterday
RubySMTPEmailMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You can send e-mails through your websites and servers.
  • You can run the mail server infrastructure on your own servers.
  • You can set up an open source email management system.
User reviews
  • • NeutralHacker News

    Postal: Open source mail delivery platform, alternative to Mailgun or Sendgrid

    “Is this more than an SMTP server? Those are services designed to send emails as an API service for many different parties. Is that what "Postal" is? Or is it a another SMTP server like Postflix or something? It's not at all clear from your description...”

  • • NeutralHacker News

    ZLibrary domains have been seized by the United States Postal Inspection Service

    “Maybe the Postal service is where the copyright owners had enough friends to go after z-lib.”

MA

mailhog · Email & CRM / Mailchimp Alternatives

STARS16.2K
FORKS1.2K
COMMITS—
CONTRIBUTORS39
VERSIONv1.1.0-beta1
UPDATED2 yr ago
Email TestingSMTPSelf-HostedGoMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • Capture and display the email sent by the application without forwarding it to a real server in the web interface
  • Send captured emails to their actual address via a configured SMTP server
  • HTTP lists emails via API, retrieves their contents, or deletes them from the system
Heads up
  • • Last update 2 years ago
User reviews
  • • NeutralHacker News

    Preview emails with letter_opener, MailCatcher and MailHog

    “hey HN, I recently published an article going deep into email previewing (in Ruby on Rails, but I think it's relevant beyond Rails). MailCatcher ( ) and MailHog ( ) are super handy and easy to run locally. Both spin up an SMTP server which you can direct mail to, and give you a…”

  • • NeutralGitHub Issue

    html email rendering as plain text

    “When MailHog receives an email, which is html, it renders it as "plain text". I don't know why this happens, and how to render it as html. Here is an example of part of the headers, as well as a screenshot: ``` Content-Transfer-Encoding: quoted-printable Content-Type: text/html;…”

MA

axllent · Email & CRM / Mailchimp Alternatives

STARS10.8K
FORKS372
COMMITS—
CONTRIBUTORS44
VERSIONv1.9.9
UPDATEDtoday
GoDev ToolsEmail TestingMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You can review captured emails in the HTML format, in the raw source code, or in the modern web interface with attachments.
  • You can use REST API for automated integration tests and get web socket notifications for incoming new mail.
  • You can test incoming messages via the SMTP server, and check email compatibility by checking for HTML and connection.
User reviews
  • • NeutralHacker News

    Mailpit – An email and SMTP testing tool with API

    “My work machine is prohibited from connecting to port 25 outside of the accepted work systems. When on VPN, I can't even connect to port 25 within the local networks. docker run -d --name=mailpit --restart unless-stopped -p 8025:8025 -p 1025:1025 axllent/mailpit I can connect to…”

  • ↑ PositiveHacker News

    Mailpit – An email and SMTP testing tool with API

    “Same, I'm using it in CI/CD for full E2E tests of web apps in combination with Playwright for app interaction, and it's awesome. Same test flow can nicely simulate user interactions and verify that emails with the correct content go out from the backend, all in seconds within a…”

HI

pimalaya · Email & CRM / Mailchimp Alternatives

STARS7.6K
FORKS260
COMMITS0
CONTRIBUTORS0
VERSIONv2.2.1
UPDATEDyesterday
cliclientEmailgpgApache-2.0

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • Posta kutularını, zarfları, bayrakları, mesajları ve ekleri terminalden yönetebilirsin
  • IMAP, SMTP, ManageSieve, JMAP, Gmail veya Microsoft Graph arka ucuna bağlanabilirsin
  • TOML ile birden fazla hesap tanımlayıp --json çıktısını betiklerinde kullanabilirsin
User reviews
  • ↑ PositiveHacker News

    Himalaya: CLI to Manage Emails

    “I think the README is missing some examples of what this can do. I used it for a script that marks every mail as seen: #!/bin/bash while true; do # Run the command and capture its exit code result=$(himalaya envelope list --folder INBOX --page 1 --page-size 100 --output json not…”

  • • NeutralHacker News

    Himalaya: CLI to Manage Emails

    “Genuine question - the HN title says "CLI to..." but looking at the GitHub repo I don't see any CLI-centric documentation. I do see $ himalaya envelope list --account posteo --folder Archives.FOSS --page 2 and a screenshot that looks like PINE. Is that screenshot interactive…”

Verified against README · Oct 30, 2026 · source

MA

MailKit

New65

jstedfast · Email & CRM / Mailchimp Alternatives

STARS6.9K
FORKS866
COMMITS0
CONTRIBUTORS0
VERSION—
UPDATEDtoday
c-sharpdkimEmailimapMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • CRAM-MD5, NTLM, SCRAM-SHA-256 ve XOAUTH2 gibi SASL mekanizmalarıyla kimlik doğrulayabilirsin
  • SMTP ile e-posta gönderirken SSL/TLS ve istemci sertifikası kullanabilirsin
  • IMAP veya POP3 ile posta kutusuna asenkron ve iptal edilebilir API'lerle erişebilirsin
Heads up
  • • No published release
User reviews
  • • NeutralGitHub Issue

    How can I implement service-to-service authentication with Office365 using the OAuth2 SASL mechanism?

    “Hi, I am trying to send email from a server application via Office 365 using OAUTH2 using MailKit with the client credentials flow. I have tried to resolve for several days so as not to waste your time - but am now admitting defeat. Here's the code I have so far: SmtpClient…”

  • • NeutralGitHub Issue

    Support for CoreCLR

    “Will there be any support for the new core clr? Also, it would be sweet if we could configure this library with smtp defaults via environmental variables as this is a part of vnext.”

Verified against README · Oct 30, 2026 · source

MA

maildev · Email & CRM / Mailchimp Alternatives

STARS6.2K
FORKS566
COMMITS—
CONTRIBUTORS90
VERSIONv2.2.1
UPDATED1 mo ago
Email TestingSMTPSelf-HostedNode.jsMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • During development, you capture the email sent by the project on the MailDev SMTP server and examine it in the web interface running on your machine.
  • For the SMTP server and web interface, you define custom IP, port and SSL certificate configurations.
  • By storing incoming emails in a specific directory, you manage data over the maximum email quota.
User reviews
  • • NeutralGitHub Issue

    I've created a fork with improvements & PR merges

    “Hey all — I've created a fork of this project with various improvements and also some PR merges. You can check it out at [ I've created my own fork because this project seems abandoned, and I wanted some of the features that were not implemented (mostly persistent storage and…”

  • • NeutralGitHub Issue

    Unhealthy maildev container in docker compose

    “``` ➜ docker ps | grep mail 7a82025c0d2e maildev/maildev "bin/maildev" 4 minutes ago Up 4 minutes (unhealthy) 1025/tcp, 1080/tcp maildev-1 ➜ docker compose logs -f maildev maildev-1 | MailDev using directory /tmp/maildev-1 maildev-1 | MailDev webapp running at maildev-1 |…”

Verified against README · Oct 25, 2026 · source

MO

mox

95

mjl- · Email & CRM / Mailchimp Alternatives

STARS5.9K
FORKS236
COMMITS—
CONTRIBUTORS19
VERSIONv0.0.9
UPDATED3 days ago
Email ServerSMTPIMAPJMAPMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You manage domain and account configurations through the web management panel.
  • You do a spam classification of incoming emails with Bayesian filtering and reputation tracking.
  • With built-in web server and API support, you automate email sending and receiving processes.
User reviews
  • ↑ PositiveHacker News

    Mox – modern, secure, all-in-one email server

    “set this up today, the documentation is useful and the quickstart very helpful, the dns stuff pretty much works exactly as it's supposed to and is just a bunch of copypasting (in my registrar's ui). specifically for mox there was some things i would have liked to see: explain…”

  • • NeutralHacker News

    Mox – modern, secure, all-in-one email server

    “After 21 years of hosting my own email server, starting with roll-your-own (anyone else remember sendmail.cf?) and moving to boxed solutions such as mox or mailcow, I gave up. Maintaining IP reputation and keeping up with the neverending set of arbitrary rules (spf, dkim, etc) I…”

HA

haraka · Email & CRM / Mailchimp Alternatives

STARS5.6K
FORKS719
COMMITS—
CONTRIBUTORS215
VERSIONv3.3.2
UPDATEDtoday
Node.jsSMTPEmail ServerMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You can customize SMTP operations with JavaScript using the plugin architecture.
  • You can install MTA or MSA for authentication and filtering with DKIM plugins.
  • With the built-in outgoing distribution engine, you can automatically queue the sending of mail marked as relays.
User reviews
  • ↑ PositiveHacker News

    Haraka - a Node.js mail server

    “node.js is Evented I/O. It might not be a perfect match for mail server. Not like in Comet or other similar situations, SMTP sessions are highly batched and not that human-interactive. There might be very little inactive open connections on a typical mail server. But based on…”

  • • NeutralHacker News

    Haraka - a Node.js mail server

    “Nice. Looks like a Node.js port of qpsmtpd - Edit: Just found that author has noted that Haraka is quite similar to Qpsmtpd.”

RE

unlayer · Email & CRM / Mailchimp Alternatives

STARS5.3K
FORKS804
COMMITS0
CONTRIBUTORS0
VERSIONv2.1.3
UPDATED2 days ago
TypeScriptReactEmail EditorUI ComponentMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You add a drag-and-drop email editor to your application with a single component.
  • You upload and edit existing designs and export them as sensitive HTML.
  • You listen to editor events and customize the configurations to the requirements of the application.
User reviews
  • • NeutralGitHub Issue

    I have my premade HTML template , i want to convert into json design , How can i do that ?

    “I have my premade HTML template , i want to convert into json design as unlayer does , how can i convert my html to JSON design compatible to unlayer ?”

  • • NeutralGitHub Issue

    Module not found: Can't resolve 'styled-components'

    “After I have installed the package, the compiler gives to me this error, anyone knows how fix it??”

CE

emailmonday · Email & CRM / Mailchimp Alternatives

STARS5.1K
FORKS696
COMMITS0
CONTRIBUTORS0
VERSION3.4.1
UPDATED1 mo ago
HTMLEmail TemplatesResponsiveNewsletterMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • You optimize email layouts for smartphones and small screens.
  • You use fluid, sensitive, or hybrid templates that can work on different email clients.
  • You build custom e-mails by combining and nesting code blocks.
User reviews
  • • NeutralHacker News

    Paid Cerberus 'lifetime' licenses are expiring

    “Cerberus also allows you to do things such as set off an alarm on the phone, take a photo using the camera, and a few other things. I don't think Google's solution does all that. In addition, a quick test looks like using Google's service triggers a notification on the device,…”

  • • NeutralHacker News

    Paid Cerberus 'lifetime' licenses are expiring

    “>> Quite frankly we did not think Cerberus would last that long! Oh, I get it. When they said "lifetime license" they meant Cerberus' lifetime, not the user's lifetime. They just somehow survived longer than they thought they would. /s”

MA

FGRibreau · Email & CRM / Mailchimp Alternatives

STARS1.9K
FORKS315
COMMITS2.2K
CONTRIBUTORS205
VERSIONv6.0.9
UPDATED5 days ago
JavaScriptEmail DoğrulamaMultilingualSpam EngellemeMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • Verify the format of email addresses via validator.js and PHP built-in filters
  • Detect and block temporary and disposable email addresses like Yopmail
  • Customise verification by adding your own dataset to the list.txt file
User reviews
  • ↓ NegativeGitHub Issue

    Go implementation

    “I am currently working on a Go implementation in my fork and most of the code and tests are done. The problem I am facing is how the code for each language implementation is generated from a template. For example, in the Go implementation, we would have `mail_check.tmpl.go`…”

  • • NeutralGitHub Issue

    Add support for ~2000 alternative domains from mailinator?

    “Add support for ~2000 alternative domains from mailinator?”

TR

truemail-rb · Email & CRM / Mailchimp Alternatives

STARS1.3K
FORKS72
COMMITS239
CONTRIBUTORS2
VERSIONv3.3.1
UPDATED15 days ago
RubySMTP DoğrulamaMX KayıtREST APIMIT

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • Confirm email addresses via regex patterns, DNS records, and SMTP links
  • You configure verification processes using whitelist and blacklist rules
  • Using the Truemail library, you perform controls on the host you work on.
Heads up
  • • Few contributors (2)
User reviews
  • • NeutralGitHub Issue

    [QUESTION] Is there any way to dynamically require net-smtp for ruby 3?

    “I understand that a lot of classes net-smtp, digest, and others have been moved from builtin classes to gems in Ruby 3. As a result of that truemail now requires net-smtp as a dependency, which in turn requires digest as a dependency. So when loading truemail v2.6+ on an app…”

  • • NeutralGitHub Issue

    [FEATURE] Question about server behind load balancer

    “Hi, first of all thanks for the gem! It is really useful. I can't find where I can ask question except here. I'm not sure how to perform SMTP validation when server is behind load balancer with internal IP only. `Truemail.host_audit` always fails because server doesn't have…”

AP

apache · Email & CRM / Mailchimp Alternatives

STARS1.1K
FORKS508
COMMITS—
CONTRIBUTORS150
VERSIONpre-3.1.0
UPDATEDtoday
Email ServerSMTPIMAPJMAPApache-2.0

Common commercial products in this category: Mailchimp, HubSpot, Salesforce

What can it do?
  • Install a JVM-based mail server that supports IMAP, SMTP, JMAP, and POP3 protocols
  • Customise email filtering and routing rules using James Mailet Container
  • Run distributed email infrastructure with Cassandra, S3, OpenSearch and RabbitMQ components