quota-status fails when size=0 from Postfix

[dovecot at ptld.com]

> At least from Thunderbird, yes. But SIZE=… does not seem to be a
> mandatory addition to the RCPT-TO line. Perhaps other mail clients do
> not use SIZE either. Just guessting.


http://www.postfix.org/SMTPD_POLICY_README.html
The "size" attribute value specifies the message size that the client 
specified in the MAIL FROM command (zero if none was specified). With 
Postfix 2.2 and later, it specifies the actual message size after the 
client sends the END-OF-MESSAGE.

Okay, it looks like if you are using an old version of postfix then 
postfix does rely on the client telling it the size of the email. But 
with postfix version 2.2 or newer postfix computes the size itself.