I'm looking for an extremely lightweight mail server to handle IMAP/POP3 connections. Maildir backend preferably, with multiple authentication modes (SQL, LDAP, etc).
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.
If you are using *nix for your platform, dovecot is pretty much the standard. Nearly every unix distro has it available in its ports / package management system.
If you are on Windows, hmail may be a fair choice.