GNU mailutils version 3.17 is available for download. This is a maintenance release, including some new features:
Use of TLS in pop3d and imap4d
If not explicitly specified, the TLS mode to use (ondemand, connect, etc.) is derived from the configured port. E.g., for imap4d, port 143 implies ondemand mode, and port 993 implies connection mode.
The global tls-mode setting is used only when the mode cannot be determined otherwise, i.e. neither per-server tls-mode is given nor the port gives any clues as to the TLS mode to use.