You may find some Plugins if you use a front-end like round cube.
I recall seeing a field in the postfix MySQL database.
I'm not sure on Maildirs since mails would be delivered and timestamps changed even if user is not logging in.
Cheers/DP
On Fri, May 17, 2019, 18:21 Lefteris Tsintjelis via dovecot <dovecot@dovecot.org> wrote:
I am using dovecot virtual maildir accounts. Is it possible to find last
day of login for an account by checking the last modification time of
the maildir files?