I just migrated from Debian 5 and Zimbra 7.2 OS to Ubuntu 12.04 and Zimbra 8 OS.
Everthing work fine, I made my back up with Zextras Migration Tool and all the information it's ok. But, like most of my users (99%) use Outlook to check their e-mail I was making test and I was unable to stablish m session, outlook said me: The session canno be stared at the POP server. ERR -invalid command.

Someone has any idea about what could be the problem?

I'm a new zimbra user.

Thank you