Top 11 Open-Source Alternatives to SMTP

The top open-source alternatives to SMTP are Mailgun, Postmark, and Amazon SES. One of the criteria for ordering this list is the number of mentions that products have on reliable external sources. You can suggest additional sources through the form here.

Mailgun Landing Page
1

Mailgun

A set of powerful APIs that enable you to send, receive and track email from your app effortlessly whether you use Python, Ruby, PHP, C#, Node.js or Java.
Pricing:
- Open Source
#Email Delivery #Transactional Email #Email Marketing 11 social mentions
Postmark Landing Page
2

Postmark

Postmark is the easiest and most reliable way to be sure your important transactional emails get to the inbox. Simply & reliably parse recieved email to JSON for your webapp.
Pricing:
- Open Source
#Email Delivery #Email Marketing #Email Marketing Platforms 49 social mentions
Amazon SES Landing Page
3

Amazon SES

Scale your business email & marketing messages with Amazon Simple Email Service (SES), a cost-effective and reliable cloud email service. Sign up today.
Pricing:
- Open Source
#Email Delivery #Email Marketing #Transactional Email 65 social mentions
Sparkpost Landing Page
4

Sparkpost

Deliver your app and website emails on time and to the inbox. Trusted to send 25% of the world's non-spam email. Email delivery for companies big and small.
Pricing:
- Open Source
#Email Marketing #Email Delivery #Email Marketing Platforms 3 social mentions
drill.software
5

Drill

Search files without indexing, but clever crawling
Pricing:
- Open Source
#Email Marketing #Email Marketing Platforms #Newsletter Marketing
Exim Landing Page
6

Exim

Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet.
Pricing:
- Open Source
#SMTP Server #Email #MTA
OpenSMTPD Landing Page
7

OpenSMTPD

OpenSMTPD is a FREE implementation of the server-side SMTP protocol as defined by RFC 5321, with...
Pricing:
- Open Source
#SMTP Server #Email #MTA 2 social mentions
PHPMailer Landing Page
8

PHPMailer

Email sending library for PHP.
Pricing:
- Open Source
#Email Marketing #Email Delivery #Transactional Email
Zoho Campaigns Landing Page
9

Zoho Campaigns

Smart email marketing software that helps you reach your target audiences, engage in a personalized way, and grow your brand presence.
Pricing:
- Open Source
- Freemium
- $25.0 / Monthly (up to 2500 contacts, unlimited emails)
#Email Marketing #Email Marketinng Automation #Email Workflow
Folderly Landing Page
10

Folderly

Folderly is an all-in-one email deliverability platform to supercharge your email performance. Locate, solve, prevent email deliverability pitfalls, and ensure that your emails reach the Inbox folder.
Pricing:
- Open Source
- Paid
- Free Trial
- $120.0 / Monthly (Folderly Premium)
#Email Deliverability #Email Marketing Platforms #Email Marketing 60 social mentions
Mailtrap Landing Page
11

Mailtrap

Email Delivery Platform that delivers just in time.  Great for businesses and individuals.
Pricing:
- Open Source
- Freemium
#Office Suites #Email #Email Testing 50 social mentions