[Dovecot] Dovecot and CAPITALISATION = grrrr ;-(

[Ben]

Hello,

As far as I'm aware, email is case insensitive ?

Dovecot however, seems to be taking offence at the fact that someone is 
sending mail to user at SOMEDOMAIN.XYZ.

Postfix has no issues handling it, it when it gets passed over to 
Dovecot LMTP that I get log lines such as :

Sep 17 13:48:22 ukc-vm02-mx01 dovecot: auth: 
passwd-file(user at SOMEDOMAIN.XYZ): unknown user

However user at somedomain.xyz *DOES* exist in the passwd file.  Just not 
with a capitalised domain !

I am confused.

Ben