Silent rejection of some some domain emails

[iliasn]

This is a serious problem that seems to affect some (not all) of the emails hosted on one subscription's domain.
Some mails from a@domain.com to b@domain.com are silently rejected (no bounce to sender).
This is plesk panel 11.0.9

The only clue at this point is some logs is

Apr 18 16:08:35 xx postfix/qmgr[1555]: B3DE07940DA: from=<webmaster@xx.gr>, size=631, nrcpt=1 (queue active)
Apr 18 16:08:35 xx postfix-local[2776]: postfix-local: from=webmaster@xx.gr, to=user@xx.gr, dirname=/var/qmail/mailnames
Apr 18 16:08:35 xx dk_check[2785]: DK_STAT_NOSIG: No signature available in message
Apr 18 16:08:35 xx postfix-local[2776]: handlers_stderr: PASS
Apr 18 16:08:35 xx postfix-local[2776]: PASS during call 'dd52-domainkeys' handler
[B]Apr 18 16:08:35 xx postfix/pipe[2781]: B3DE07940DA: to=<user@xx.gr>, relay=plesk_virtual, delay=1193, delays=1193/0.02/0/0.06, dsn=4.3.0, status=deferred (temporary failure. Command output: Usage: /usr/bin/deliverquota [-c] [-w percent] maildir 4.2.1 Message can not be delivered at this time )[/B]

I show also a report somewhere else.
It has a solution there, that i didn't try, that involved commenting main.cf lines. but I am not sure if it is safe + the are reset after plesk auto updates.

 

[iliasn]

Fixed

THIS was a fault of me.
I migrated the maildirs from cpanel and for some reason, on some accounts the .qmail hidden fail was not there, thus the message.
I created a .qmail file (in the same folder where Maildir folder for a user exists) and this is fixed
The contents of .qmail are as follows (takes from working accounts)

| true
| /usr/bin/deliverquota ./Maildir