UW IMAP

UW IMAP is the reference server implementation of the IMAP protocol, developed at the University of Washington.

Although it has not been actively developed in many years, it still works well as a basic IMAPS server. (For other IMAP servers, see Mail server#Software.)

Installation

Install c-client^AUR. It does not use a configuration file.

Note: c-client is a split package containing both UW IMAP and its client, you can install both or just one of the packages depending on your needs.

Configuration

Although it was originally designed to be used with inetd, on modern Arch systems a better solution is to use a systemd socket file:

/etc/systemd/system/imaps.socket

[Unit]
Description=IMAP Server Activation Socket
Documentation=https://www.washington.edu/imap/

[Socket]
ListenStream=0.0.0.0:993
Accept=true

[Install]
WantedBy=sockets.target

Also, a corresponding .service file needs to be created:

/etc/systemd/system/imaps@.service

[Unit]
Description=IMAP Server

[Service]
ExecStart=-/usr/bin/imapd
StandardInput=socket

UW-IMAPD uses PAM, so a PAM authorization file will also need to be created. This example will provide authentication using standard system passwords:

/etc/pam.d/imap

auth		required	pam_unix.so
account		required	pam_unix.so
session		required	pam_unix.so

Enable and start imaps.socket and test.

SSL

A generic SSL certificate and key will be created at /etc/ssl/certs/imapd.pem if it does not yet exist. This can be replaced with a signed certificate for the specific server.

Warning: Self signed certificates, like the one automatically generated, are prone to MITM attacks, ensure you use a signed certificate on a production server.