On 20. Oct 2020, at 5.31, Victor Sudakov <vas@sibptus.ru> wrote:

Sami Ketola wrote:

On 19. Oct 2020, at 18.54, Victor Sudakov <vas@sibptus.ru> wrote:

Dear Colleagues,

Is there a file or directory within a user's Maildir, whose date of
modification or access indicates the last time the user accessed his/her
E-mail via IMAP or POP3?

I'd like to figure out the time a user last logged in into his/her mail
account, not the last time a mail was delivered to the INBOX.

This information is probably available in the log, but a file which is
touched each time a user accesses his/her mail, is more convenient.

Not directly but you might want to take a look at this: https://doc.dovecot.org/configuration_manual/lastlogin_plugin/

Hello Sami,

I have seen this but I do not want this information in a database. If
you know how to make the lastlogin_plugin write to a local file, that
would be very helpful. Even a local sqlite database would do.

The documentation for the plugin seems very scarce.