Autor: Eli Data: A: exim-users Assumpte: [Exim] Unable to send additional 250 lines at EHLO/HELO time (via HELO ACL)
I am trying to implement an ACL that will warn clients/servers that do not
specify a proper EHLO/HELO greeting of such and impose a time delay (because
they're probably spammer programs).
Of course, as soon as I use a warn with a message in the acl_smtp_helo ACL,
it says I can't send any headers at this time. However, RFC2821 says that
EHLO/HELO replies may be multi-lined. I could just put my EHLO/HELO check
at a later time (say, RCPT time), but then that would be a little out of
sequence for issuing warnings - I'd rather be able to do it in sequence.
I also noticed there's no way to give a message, and THEN delay, although I
guess this could be worked around by making 2 statements (first being the
msg, the second being a delay both triggering on the same conditions). Any
reasons why delays aren't issued in the order they're specified in the ACLs?
Maybe an "delay_inline" option could be added, to specify a delay as it's
hit while processing an ACL?
Is there a reason why no messages can be sent at EHLO/HELO time (other than
to prevent people from sending improper multiline replies)? If there's no
way to get the ability to add custom messages to the 250 reply at this time,
is there some other way to edit the message templates that are in Exim?
Which brings up another question (which might be a better over-all solution)
- would changing the (I assume to be...) hard coded error/warning messages
that are tied to the various status codes to a configurable template system
be something that can be on the wish list?