[Dovecot] Authentication with lower case username ONLY

[Leander S.]

  Am 15.09.10 19:07, schrieb Jerry:
> On Wed, 15 Sep 2010 18:50:47 +0200
> spamvoll at googlemail.com articulated:
>
>> 2010/9/15 Leander S.<info at netocean.de>:
>>>   Hi,
>>>
>>> how do you guys force your users to authenticate with lower case
>>> letters ONLY? Or convert it?
>>> Is there a SASL Option to force that - or are you using scripts
>>> i.e. a bash script in combination with the command "tr" ... or a
>>> third solution I didn't think of yet?
>>>
>>>
>>> I'm using Postfix / Dovecot combination. Postfix is told to use
>>> Dovecots SASL Service to authenticate it's users.
>>> For my outgoing eMails I already wrote a script with tr which forms
>>> upercase usernames to lowercase ones ... but it's not enough.
>>> SpamAssassin is still confused and writes uppercase letters in it's
>>> Database etc. ... So that's why I'm looking for a more universal
>>> solution.
>>>
>>>
>>> P.S. I would basically prefer a convertation - but I would also be
>>> fine with a forced lower case auth system.
>> check http://wiki2.dovecot.org/Variables ->  Modifiers
>>
>> You can apply a modifiers for each variable (e.g. %Us = POP3):
>>
>>      * %L - lowercase
>>      * %U - uppercase
^^ Thanks. That's what I have already: "username_format: %Lu" But I 
didn't know about Service restriction. Is it possible to give only 
several users POP and the others IMAP access without a second instance?


> Out of morbid curiosity, why do you feel the need to convert the user
> names to lower case?
>
Well the reason is quite easy to describe: I have SpamAssassin running 
which is connected to a SQL Backend. So now how should I make sure 
user_prefs match if people can set up user_prefs as their Username 
offers combinations of switching between upper and lower case. In the 
end it means having a horrible mess in the Database PLUS having an 
unsatisfied customer cause he complains about his rules only working 
sporadically ...

But I figured so far - since I have that %Lu option included already, 
that I have to optimize my SpamAssassin therefore ... cause for "awl" it 
seems to pick out the Data from the Mail itself instead of getting it 
hand over in lower case from Dovecot/Postfix ...