On Apr 20, 2020, at 18:13, @lbutlr <kremels@kreme.com> wrote:

On 20 Apr 2020, at 04:27, mj <lists@merit.unu.edu> wrote:

Hi Ralph!

Thanks for your reply!

On 4/20/20 12:19 PM, Ralph Seichter wrote:

I suggest you don't use Sieve for this, but simply configure Postfix
to reject messages to @old.domain.com with the desired message. MTA
rejections signal clearly that the message has not been delivered, and
you can also include an URL pointing to a web page with more detailed
information.

However, this means those emails are not actually delivered anymore.

Yes, with a rejection message that informs why the message was not delivered. This is the best thing you can do as it will force people to actually change the email.

If you delay this by doing something temporary, all you are doing is delaying it. Once you cut off the old email you’ll be in the exact same situation you are in right now, as very few people will update email addresses.

If all you do now is autrespond with an automated message, most people will never see that message. And if your auto-responder is paying the message is not read or forwarded, what are you gaining? It is much better for the sender to get an actual error which they are much more likely to see.

The other thing you can do is NOMX the old domain.



-- 
in the long run there's still time to change the road you're on