wietse:
This turned out to be easier than expected. Manpage fragment for
Postfix 2.12-20140907:
confirm_delay_cleared (default: no)
After sending a "your message is delayed" notification,
inform the sender when the delay clears up. This can result
in a sudden burst of notifications at the end of a prolonged
network outage, and is therefore disabled by default.
Adding this required only minor extension of existing infrastructure.
The feature is also available as a patch for older Postfix versions at
ftp://ftp.porcupine.org/mirrors/postfix-release/experimental/feature-patches/20140907-confirm_delay_cleared-patch
Hello,
thanks for the patch. I like to use it with postfix-2.11.1. At a first
view it works as expected.
But imagine th following scenario: client <-> relay <-> destination
- client send a message requesting DSN on success and failure.
Explicit not for delay.
- the relay has
delay_warning_time 1h
confirm_delay_cleared = yes
- the destination if offline
- the relay hold the message for two hours and do not send a "your
message is delayed" notification
- the destination go online
- the relay forward the message
- the destination send a "your messages is delivered"
But just here the relay also send a "your messages is delivered".
That's unexpected to me. I'm unsure if I like this.
If I read the documentation, it may be a bug because no delay warning
was sent.
Anyway: I checked, the relay do not send a success message if there
was no delay at all.
Also interesting to test: what happen if relay is greylisted and
deliver to a fallback_relay.
( that may have similar setting or not )
Andreas
