[ Apologies if this is a duplicate -- I wasn't on the list when I posted it earlier, and I think the first copy has been swallowed.... ]
I want to write a recipient ACL in which a callout is made to test the deliverability of the recipient address and, (a) if the recipient is definitely deliverable, the ACL returns `defer'; (b) if the recipient is definitely undeliverable, the ACL returns `deny'; and (c) otherwise it returns `accept'. (The application is for a secondary MX host where it is not practical to apply the same content filtering etc. conditions as on the primary; therefore, in the most common case where the primary is up -- and therefore the recipient test succeeds -- I want to return 451; if the address would in any case be undeliverable, 550; and otherwise accept the mail.) So, I tried something like this: defer domains = +relay_domains verify = recipient/callout,nocache message = Primary MX for $domain is up, please try that deny domains = +relay_domains !verify = recipient/callout message = Recipient [EMAIL PROTECTED] not deliverable accept domains = +relay_to_domains ... and in the first two cases it works. Unfortunately, in case (c), where the remote host is down, the defer condition is failed and returns ``451 Could not complete recipient verify callout''. My reading of the spec (ยง39.32) is that this is the design behaviour: verify = recipient/callout conditions are special in that a defer result will immediately cause the whole ACL to defer. The defer_ok modifier doesn't help in this case as it causes the condition to return true, which would mean that the `defer' stanza fires when the remote host is *down*, which is exactly wrong. What I'd like in this case is for the verify = recpient condition to result in a failure with an appropriate value in $recipient_verify_failure or somewhere else that I can test it. Is there a way to do this? (I actually have an interim solution to this which uses perl to perform the callout, but that's horrid -- one implementation of SMTP per program is enough....) -- ``The efficiency of the rocket launcher team was also very impaired.'' (commentary on film of British troops given LSD as part of a 1960s chemical warfare experiment) -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/