[Dovecot] turn Usernames in Lowercase

[Leander S.]

  Hi,

I'm just curious how to force usernames to be modified to lowercase 
letters if one mixes uper and lower case letters to one salad?
Cause my SpamAssassin gets confuesd and treats different spellings of 
Usernames as different Users - which is uncool.
I've heard about something you can add in your dovecot.config to enforce 
lowercase letters only.


Thanks