No external mail since 8.1.1

[TauTau]

Hi,

since I upgraded my Plesk to 8.1.1 in a manual manner (see here http://forum.swsoft.com/showthread.php?s=&threadid=47222)
I don't receive any mails from external anymore. A local php mailer works though. Any advice where I should check? I don't see anything in the mail logs about denied mails so far...