Courier IMAP and Parallels Plesk 9.2.3 upgrade

Something really quick  about upgrading your Parallels Plesk to 9.2.3.

You will probably find that your emails will not work as doing an upgrade seems to reset a variable in the Courier Imap config file.

The error you are most likely to get is something like:

There may be a problem with the mail server or network. Verify the settings for account "email address" or try again.
The server returned the error: The server "mail.domainname.co.uk" refused to allow a connection on port 143.

This is a response that 1and1 gave me who had to pass over to Parallels as they could not solve.

 Errors in /usr/local/psa/var/log/maillog indicated that there were issues with command line parameters on IMAP start:

Nov  6 17:03:29 s15293703 imapd: Invalid -maxperip option.
Nov  6 17:03:29 s15293703 imapd-ssl: Invalid -maxperip option.

I have checked configuration of IMAP services in /etc/courier-imap and found that 'MAXPERIP' parameter had been commented in /etc/courier-imap/imapd file thus empty value was passed to imapd start script and error occured.

I have set MAXPERIP to default value (4) and then IMAP server started and login into Webmail is available now.