Cannot log in to freshly installed Mailpile


I have installed Mailpile + Multipile today and set it up following these instructions:

When create user, I got these output:

./ --user g --start
==> sudo -iHu "g" -- /usr/bin/python2.7 "/usr/share/mailpile/multipile/mailpile-" --start --port="53563" --host=""
sudo: unknown user: g
sudo: unable to initialize policy plugin
==[ FAILED! Exit code: 256 ]==
==> chown -R www-data:www-data /var/lib/mailpile/apache
==> chmod go+rwxt /var/lib/mailpile/pids
===[ SUCCESS! ]===

Anyway, if I try to enter to myserver/mailpile, I see ‘Your Mailpile may not be running’ message. If I try to open, it redirects to myserver/mailpile/

Important to khow that I have Nextcloud running simultanneuously on this server (because my VPS do not support docker).