I recently moved to a new VPS provider and currently running a couple of WIP joomla sites. I have configured google apps email on the sites and everything was working fine till about Apr 5, emails were being sent out from sites.

Now after Apr 5, when I logged in, I saw that WHM was automatically upgraded to version 11.32. Then my emails stopped working on all the joomla sites hosted on the VPS with the error

"SMTP Error! Could not authenticate"

Joomla mail settings are the usual

Mailer: SMTP Server
From Email: admin@domain.com
From Name: name

SMTP Authentication: Yes
SMTP Security: SSL
SMTP Port: 465
SMTP Username: admin@domain.com
SMTP Password: [-password-]
SMTP Host: smtp.gmail.com

The same configuration is working on different joomla sites on different servers. I have contacted my host and they are also trying to figure out the problem, but no luck till now.

Any suggestions would be appreciated.