Charlie Orford:
>Hi Wietse,
>
>Although the address caching should have worked as you describe,
>we found that it failed for a number of addresses despite the fact
>that these addresses had received email in the last 31 days (most
>had in fact received mail in the last 24 hours).
To report a problem with the address verify cache, you need to show
a record that the same recipient is first accepted, and then that
it is rejected before the recipient was supposed to expire. Also
include "postconf -n" output for that system.
If no such problem exists, then we know that cache expiration
has nothing to do with the issue and we can move on.
When the address verify cache works properly, it should become
populated over time (by spammers, by legitimate sites that have
very short SMTP timeouts, or by legitimate sites that try to deliver
to the backup after the primary replies with a 4xx response).
There is no need to turn Postfix into a backscatter source by
accepting all mail when the primary is down. Just set the cache
expiration time to 100 days or so. Meanwhile I'll see if it is safe
to purge a recipient from the cache when the primary says that it
no longer exists. Maybe Postfix needs to wait for two negative
responses.
Wietse
