For the last couple of months one of our servers just stops sending mail. Its an ISPConfig 3.0.5.4p8 on Ubuntu 16.04 itself on an OVH Proxmox 4 LXC. There are 25 active websites on the serveur, but no email accounts (we use separate mailers for that), mostly Dolibarr quote and invoice management sites. So it can be a couple of days before we see that clients quotes haven't been arriving at their prospects. Embarrassing! Nothing special in the logs. Restarting Postfix does nothing. Rebooting the serveur and flushing works, then a couple of weeks later the problem comes back. I know it's not much to go on but has anyone else got this too ? Regards, Thomas CARTER, Cergy Internet
I would install munin and monit to monitor the server more closely to find the reason why the mail system stops and to let it restart postfix automatically in such a case.
