I'm using sendmail with milter filter (by TCP socket) to handle email
messages(checking and changing header).
I often have this messages in maillog:

Jan 19 12:46:53 mails sendmail[31511]: l0JBc5bp031511:
from=<nremedy@wakm.com>, size=13106, class=0, nrcpts=2,
msgid=<000e01c73bc8$1dbe57a0$0019c524@marcsin2uibj rd>, proto=SMTP,
daemon=MTA, relay=mail.prova.it [152.123.22.12]
Jan 19 12:46:53 mails sendmail[31511]: l0JBc5bp031511:
milter_read(smrazor): cmd read returned 0, expecting 5
Jan 19 12:46:53 mails sendmail[31511]: l0JBc5bp031511: Milter
(smrazor): to error state
Jan 19 12:46:53 mails sendmail[32126]: l0JBc5bp031511:
to=<s.petti@mail.prova.it>,<s.nannipieri@mail.prov a.it>,
delay=00:08:00, xdelay=00:00:00, mailer=smtp, pri=73106,
relay=[10.0.2.1] [10.0.2.1], dsn=2.0.0, stat=Sent (l0JBlgqa013267
Message accepted for delivery)

I verified that message correctly arrives to recipient but in my milter
only these callbacks are called and its job is not executed:

xxfi_envfrom
xxfi_envrcpt
xxfi_abort
xxfi_cleanup

1- Why is "xxfi_abort" invoked if this message is sent to recipient
correctly ?
2- What's it meaning of "cmd read returned 0, expecting 5" ?

Riccardo wrote:
> I'm using sendmail with milter filter (by TCP socket) to handle email
> messages(checking and changing header).
> I often have this messages in maillog:
>
> Jan 19 12:46:53 mails sendmail[31511]: l0JBc5bp031511:
> from=<nremedy@wakm.com>, size=13106, class=0, nrcpts=2,
> msgid=<000e01c73bc8$1dbe57a0$0019c524@marcsin2uibj rd>, proto=SMTP,
> daemon=MTA, relay=mail.prova.it [152.123.22.12]
> Jan 19 12:46:53 mails sendmail[31511]: l0JBc5bp031511:
> milter_read(smrazor): cmd read returned 0, expecting 5

sendmail was expecting the milter to tell it something, the milter told
it nothing. Possibly the milter crashed or timed out or god knows what.
Sendmail doesnt....so:

> Jan 19 12:46:53 mails sendmail[31511]: l0JBc5bp031511: Milter
> (smrazor): to error state

it sets it to error state and continues processing the message, as per
your milter filter definiton where you have not configured it to reject
messages in the case of errors ( fail closed [in the electrical sense])

> Jan 19 12:46:53 mails sendmail[32126]: l0JBc5bp031511:
> to=<s.petti@mail.prova.it>,<s.nannipieri@mail.prov a.it>,
> delay=00:08:00, xdelay=00:00:00, mailer=smtp, pri=73106,
> relay=[10.0.2.1] [10.0.2.1], dsn=2.0.0, stat=Sent (l0JBlgqa013267
> Message accepted for delivery)

> I verified that message correctly arrives to recipient but in my milter
> only these callbacks are called and its job is not executed:
>
> xxfi_envfrom
> xxfi_envrcpt
> xxfi_abort
> xxfi_cleanup
>
> 1- Why is "xxfi_abort" invoked if this message is sent to recipient
> correctly ?

libmilter calls the abort callback if it detects that sendmail closed
the connection to it (which happens if sendmail sets the milter to
error state)

> 2- What's it meaning of "cmd read returned 0, expecting 5" ?

See above.