dovecot-gssapi 1:2.2.22-1ubuntu2.14 (arm64 binary) in ubuntu xenial

 Dovecot is a mail server whose major goals are security and extreme
 reliability. It tries very hard to handle all error conditions and verify
 that all data is valid, making it nearly impossible to crash. It supports
 mbox/Maildir and its own dbox/mdbox formats, and should also be pretty
 fast, extensible, and portable.
 .
 This package provides GSSAPI authentication support for Dovecot.