Topic: Mail service unstable, sometimes clients can't connect
=== Required information ====
- iRedMail version: v0.8.5
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Debian 6
- Related log if you're reporting an issue:
I've migrated from my hosting to a VPS with iRedMail our users, around 35.
I tested it on the weekend, it seemed to be fine.
But now clients are complaining they are receiving errors when trying to reach the mail server.
The strange thing is that I'm monitoring the server, making a TCP connection to IMAP, POP3 & SMTP, it has never failed, but my clients reported random downtimes of 10-20 minutes, after which the service restored itself without my intervention.
How can I troubleshoot this?
Which logs should I look into?
If the ports are OK, maybe it's a problem with the MySQL DB?