popa3d is a tiny POP3 daemon designed with security as the primary goal. You can read more about its design, check out the change log, or download a popa3d tarball (the latest stable version is recommended) and refer to the documentation inside.
These and older versions of popa3d, as well as related user-contributed files, are also available from the Openwall file archive. The source code of popa3d can be browsed on GitHub or via CVSweb.
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There's a mailing list where you can share your experience with popa3d and ask questions. Please be sure to specify an informative message subject whenever you post to the list (that is, something better than "question" or "problem"). To subscribe, enter your e-mail address below or send an empty message to <popa3d-users-subscribe at lists.openwall.com>. You will be required to confirm your subscription by "replying" to the automated confirmation request that will be sent to you. You will be able to unsubscribe at any time and we will not use your e-mail address for any other purpose or share it with a third party. However, if you post to the list, other subscribers and those viewing the archives may see your address(es) as specified on your message. The list archive is available locally and via MARC.
Commercial support for popa3d is available, please check out our services. We can help you install popa3d or even help you integrate it into an existing mail server and mail user database setup you might have. The latter might be a combination of our free software development and consulting services.
Contributed popa3d resources (note: we haven't audited any of these):
Patches (the popa3d 0.6+ patches should also apply to 1.0):
The use of APOP is not recommended.
The preferred way to do POP-before-SMTP is via whoson.
Obsolete patches which are no longer needed with popa3d 0.5+:
popa3d is the default POP3 server on Owl, Slackware, and distributions by ALT Linux team. popa3d is also part of Debian GNU/Linux and Gentoo Linux. popa3d was integrated into OpenBSD versions 3.0 to 5.4.
popa3d is a registered project with Open Hub.