Vesta Control Panel - Forum

Hello, see if someone can help me with this error that occurs on a vestacp server with email service.

I have configured an exim4 + dovecot on debian 9.

When we make the configuration in an email client, either Outlook or Thunderbird, the client downloads all emails through IMAP, but the server is blocked.

When it is blocked, it no longer allows you to log in, send or receive emails in Outlook or Thunderbird, however from the webmail it works correctly.

I've been looking at the exim and dovecot settings but I can't find anything that has solved the problem.

I have examined the status of the services when this happens, even the status of the server with htop and shows normal values.

For it to work again, I have to restart the entire vestacp package except the server.

Does anyone know what can happen?

You must share the dovecot.log and exim.log to verify the problems you are having and to give you an effective solution about of this problem if persist.

sysdop wrote: ↑

Fri Aug 30, 2019 3:22 am

You must share the dovecot.log and exim.log to verify the problems you are having and to give you an effective solution about of this problem if persist.

Apparently the system crashes when emails or folders are downloaded from IMAP.

Although we have not had more problems of this type, we make a few less restrictive configurations and the workload is lower.

It was also the set-up where about 20 or 30 corporate emails, were making mail and file dumps to the server, perhaps that is why the system was blocked.

Right now it seems that it no longer gives errors.

What we have noticed is a massive attempt to access the SMTP server by addresses that do not exist, using various IPs, names, etc.

And although the firewall does its job, when using diverse IP's, it is impossible to block the attack. Has this happened to anyone else?

You can change the fail2ban and the iptables for CSF firewall, it is more effective.