Sync received email with Dovecot problem on Debian 9

Hi there,
I've installed two servers in cluster following the Florian's how-to "Installing a Web, Email & MySQL Database Cluster on Debian 8.4 Jessie with ISPConfig 3.1" in Debian 9.

They work fine for the sync emails with Dovecot, when I write a new email (e.g. in Roundcube) and when I read or delete a received email: the same operation happens on both servers immediatly.

But when the master mail-server has received a new email, this one not appears on the slave mail-server until something happens in the master mail-server (e.g. the user read that email).

Does anyone have an idea to fix it?

Tanks a lot

P.S. System configuration:
Debian 9 Stretch, with Apache, Bind, Dovecot, Postfix and ISPConfig 3.1.7.p1 on each server
Cluster sync by Dovecot for emails and Unison for web sites

 

check the dovecot.conf:

Code:

mail_plugins = notify replication quota
...
protocol imap {
  mail_plugins = $mail_plugins imap_quota
}
protocol lda {
  mail_plugins = $mail_plugins sieve
  [email protected]
}
...

 

Hi Florian,
in your how-to the dovecot.conf is so:

Code:

...
mail_plugins = $mail_plugins notify replication quota
...
protocol imap {
        mail_plugins = quota imap_quota notify replication
}
...

and for protocol lda the default dovecot.conf setting is so:

Code:

protocol lda {
  mail_plugins = sieve quota
  [email protected]
}

If I change these as you've written, on both servers (and I restart Dovecot), the received emails are queued but not put in their email-boxes.

There's something wrong, have you got any ideas?

Thanks a lot

 

check the mail.log, use mailqueue and/or doveadm replicator status

 

I see that in the dovecot.conf there are two different line plugin {...} and two different line protocol imap {..}.
In the howto it was written "Open /etc/dovecot/dovecot.conf ... and add the following content".
So, is it normal to have two different lines with the same instruction or must I preserve the one in the how-to and delete the default one?

E.g. now I have both these plugin {...} so

Code:

at line 24:
plugin {
  quota = dict:user::file:/var/vmail/%d/%n/.quotausage
  sieve=/var/vmail/%d/%n/.sieve
  sieve_max_redirects = 25
}
at line 112:
plugin {
        replication_full_sync_interval = 1 hours
        mail_replica = tcp:xxx.xxx.xxx.xxx:4711
}

I must delete the plugin {...} instruction at line 24 or I preseve both (and the same for the protocol imap {..})?