I ran a test a moment ago and got this result:
Connecting to foxtrot.kis.keele.ac.uk [160.5.46.69]:25 ... connected
SMTP<< 220 foxtrot.kis.keele.ac.uk Keele University Electronic Mail Service
SMTP>> EHLO pc67.isc.keele.ac.uk
SMTP<< 250-foxtrot.kis.keele.ac.uk Hello pc67.isc.keele.ac.uk [160.5.50.10]
250-SIZE 8388608
250-PIPELINING
250 HELP
SMTP>> MAIL FROM:<csa01@???> SIZE=1459
SMTP>> RCPT TO:<doesnotexist@???>
SMTP>> DATA
SMTP<< 250 OK
SMTP<< 550 Unknown user
SMTP<< 503 valid RCPT command must precede DATA
SMTP>> QUIT
This is EXIM 4.43 with the exiscan patch. The order of the lines implies
that Exim sends a "DATA" command before it sees the response from the RCPT
command. Surely Exim shouldn't be trying to send the message unless at
least one RCPT command succeeded?
--
______ jonathan@??? Jonathan Knight,
/ Department of Computer Science
/ _ __ Telephone: +44 1782 583437 University of Keele, Keele,
(_/ (_) / / Fax : +44 1782 713082 Staffordshire. ST5 5BG. U.K.