ok, I am back...
After the upgrade and the changes described in the wiki first all seem's ok, receiving mails is fine.
But then I tried mail sending and got the following error:
Dec 13 12:05:14 mail postfix/smtpd[23043]: warning: when SASL type is "dovecot", SASL path "dovecot-auth" should be a socket pathname
Sending mails fails. And I do not see the error because the authentification part was not touched...
Can you please help me again?
Finally I found another error:
Dec 13 11:59:44 deliver(www-data): Error: sieve: failed to stat user's sieve script: stat(/var/vmail/sieve//www-data/dovecot.sieve) failed: Permission denied (euid=33(www-data) egid=33(www-data) missing +x perm: /var/vmail) (using global script path in stead)
Dec 13 11:59:44 deliver(www-data): Error: sieve: main_script: failed to stat sieve script: lstat(/var/vmail/sieve/dovecot.sieve) failed: Permission denied (euid=33(www-data) egid=33(www-data) missing +x perm: /var/vmail)
Dec 13 11:59:44 deliver(www-data): Error: sieve: main_script: internal error occurred: refer to server log for more information. [2010-12-13 11:59:44]
Dec 13 11:59:44 deliver(www-data): Error: sieve: failed to open script /var/vmail/sieve/dovecot.sieve
This occurs when the awstats cron job tries to send mail to a mailaccount which had have working sieve rules before upgrade.