Pascal Dreissen wrote:
Not only Lotus Notes, also for ex. Kerio Mailserver.
We tried to use it.. but ended up with more failures then temporary failures.
Maybe I'm just a hardass, but non-compliant mailservers like this should not be pandered to. 4xx response codes require the originating server to retry later. I would temporarily whitelist any servers that had problems with this (and contacted me), but only after telling them in no uncertain terms that they need to upgrade their MTA (Kerio fixed this apparently in Version 6.0.5 - December 14, 2004).
Sadly, I cannot roll out greylisting at the moment because I have too many users who view e-mail as an instant form of communication and cannot understand when something doesn't appear in their inbox immediately. :-(
John
