Version 3.18 of GNU Mailutils is available for download.
A short summary of changes follows.

New debugging shortcut: all
Using all in mailutils debug level specification enables all debugging categories. Syntactically, all can be used wherever an actual category name is allowed, thus, e.g., all.!=prot enables all levels except prot in all debugging categories.

mail: fix and document interaction between mailutils configuration files and mail command files.
In particular, mail variables that correspond to some mailutils configuration settings, now correctly reflect their value.

Bugfixes Minor fix in handling of the EHLO command in smtp client. * Improve docs. * Minor fix in mhn and related tests. * mail utility: use the mailer* configuration capability.