Vesta Control Panel - Forum

This happens, sometimes, if your host is doing something called "tarpitting" which helps catch spam. If that's the case, it's nothing to worry about. People more informed can correct me.

Instead of using a redirect, you can do this:

1. Create subdomain in vestaCP (eg: webmail.yourdomain.com)
2. Remember, roundcube directory is /var/lib/roundcube
3. nano /home/admin/conf/web/apache2.conf
4. Look for the section with your new subdomain
5. change:
DocumentRoot /var/lib/roundcube ...

Here's what I did to accomplish the following:
For Ubuntu 14.03

1. Use custom TLS/SSL certs for SMTP:

nano /etc/exim4/exim4.conf.template

if you have your own certificate and key, then change the lines to point to the appropriate files (key and certificate).
tls_advertise_hosts = *
tls ...