Dave C. [exim-users] <14/05/01 12:17 -0400>:
> However, there is no valid reason for a sender to supply a non-existent
> domain in the From: header, and in fact, the most common reason (other
> than just complete ignorance on the part of someone associated with the
> sending system) is becuase the message is a spam. So, blocking messages
> that dont have a valid address in the From header is a good thing.
There _is_ one other reason. When you send out autoresponders on a large
scale (say an ISP's abuse ticketing system) and want to stop people from
replying to the autoresponder (hitting reply-all instead of reply does this)
Valid envelope from, and something like autoresponder@dont-reply in the
from.
At least one ISP I know does that. OK, it's not very elegant, but it works.