Dovecot fatal error

I’m having problems with emails, sending them, connecting to the email server using rainloop etc. I did a journalctl -f | grep dovecot and got this messages.

mytinyserver dovecot[28739]: doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 98: Unknown setting: managesieve_max_line_length
Jan 11 05:33:38 mytinyserver systemd[1]: dovecot.service: main process exited, code=exited, status=89/n/a
Jan 11 05:33:38 mytinyserver systemd[1]: Unit dovecot.service entered failed state.
Jan 11 05:33:38 mytinyserver systemd[1]: dovecot.service failed.

Any suggestions on how to solve this?

I have copied the dovecot.conf file from another cyberpanel and replaced the failed one. Dovecot is running now, but if I try to login to email with rainloop i get an authentication failed message. In the email queue section I’m seeing a lot of deferred emails. What is happening ?