Ok, after FINALLY recovering from a horrible Plesk desaster, I got this error:

postfix temporary lookup failure – what the hell is that????

Here’s how I fixed it:

First of all you’ll need to know if your getting this error, so check:

# cat /var/log/mail.log

Error: open database /var/spool/postfix/plesk/transport.db: Invalid argument

Have a look through here and findout what errors you are getting. I was also getting the same but with blacklists.db.

Now follow these steps in order changing out the .db file name with the  one you need to fix

# /usr/local/psa/admin/sbin/mailmng –stop-service
# mv /var/spool/postfix/plesk/blacklists.db /var/spool/postfix/plesk/blacklists.db_
# /usr/local/psa/admin/sbin/mchk –with-spam
# /usr/local/psa/admin/sbin/mailmng –start-service

Hope that helps. Let me know how it goes