Docker image for IMAP
Provides a minimal IMAP server docker image based on our Alpine Linux 3.12 base image and Dovecot.
This image can be used to provide a simple IMAP server for testing and development.
By default, one IMAP user imap with the password imap is created.
This can be changed by setting the IMAP_USERS environment variable to a space-separated list
of username:password entries.