Consider the following SMTP-Session:
220 mx.example.com ESMTP Postfix
EHLO example.com
250-mx.example.com
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-DSN
250 SMTPUTF8
MAIL FROM:<>
250 2.1.0 Ok
RCPT TO:<test@example.com>
250 2.1.5 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
Subject: Test
Test
.
451 4.7.1 Try again later
What is a client supposed to do after this? Is he allowed to send an RSET and try another Mail?
This Question is loosely related to this rspamd issue and I am not sure who behaves wrong:
- rspamd for not handling multiple mails in one session correctly if the first delivery fails
- Postfix for not sending rspamd the correct Milter Commands
- OpenSMTPd for delivering another mail after one that already failed
