This is a list of resources for those implementing or just interested in ARC. If you are aware of a package, product or service not listed here, please let us know about it through the Contact Us form.

Groups and Mailing Lists Discussing ARC

There is also a mailing list for people writing code to implement ARC, who wish to participate in testing events. If you fall into this category, please use the Are You Implementing ARC? form and we’ll add you to that list.

Products and Services Using ARC

The products in this section allow organizations to deploy ARC, and the services listed have deployed ARC in production.

Name Description Fees?
Halon MTA Halon MTA is a Mail Transfer Agent (MTA) designed “for large-scale email services.” Free trial, commercially licensed
MailerQ MailerQ is an MTA designed to “send large volumes of email with maximum control at unparalleled speed.” Developed by Copernica. Free trial, commercially licensed
Name Description Fees?
Gmail Gmail is a free, advertising-supported email service developed by Google. It can be accessed from web browsers, desktop PCs, and mobile devices. No – ad supported
G Suite G Suite is a brand of cloud computing, productivity and collaboration tools, software and products developed by Google. They can be accessed from web browsers, desktop PCs, and mobile devices. Free trial, fee supported
Google Groups Google Groups is a service from Google that provides discussion groups for people sharing common interests. No
Microsoft Office 365 Office 365 is an suite of cloud-based services, including email, scalable from individual home users all the way to very large enterprises. Fee supported
Mailing List Managers (MLM)
Name Description Fees?
Mailman Mailman is a free MLM “for managing electronic mail discussion and e-newsletter lists.” ARC patches have been available for years, and ARC configuration directives are in the online documentation. Free, GPL licensed
Sympa Sympa is “an open source mailing list manager. It provides advanced features with a rich and secure web interface.” Free, Creative Commons Attribution-ShareAlike

Code, Libraries, and Packages That Implement ARC

This section includes libraries that include an implementation of ARC, which you can use to incorporate ARC into your software product or service. It also includes packages that implement ARC, which you can use to deploy ARC as part of your messaging infrastructure.

Libraries for Development and Integration
Package Location License
ARC Test Suite FOSS (© ValiMail)
Perl module Mail::DKIM FOSS (Perl Artistic License, GNU Public License)
Python library dkimpy FOSS (BSD-like)
C library (OpenARC) FOSS (Sendmail Open Source License)
Modules, Packages and Patches for Deployment
Name Location License
dkimpy (CLI utilities) FOSS (BSD-like)
authentication_milter FOSS (Perl Artistic License, GNU Public License)
OpenARC Milter FOSS (Sendmail Open Source License)