On 25 May 2020, at 12:48, mj <[email protected]> wrote:
> I would then ask them to move over to 993, and finally disable port 143
> altogether.
From personal experience the only way to do this is to stop listening to port
143. I dropped support for non-encrypted mail ports ages ago, and I didn't get
a single user to switch from 143 to 993 until I disabled 143.
Send an email to your users "You must make this change bu (date+2 days)" and
then drop port 143 in 2 days as promised. If you have a web server, but a large
red box on it "Can't login?" With a link to the email you sent.
(And do not allow users to send mail un-encrypted either, force them to use 587
or 465 by not accepting user mail on port 25).
--
This is Art holding a Mirror up to Life. That's why everything is
exactly the wrong way around. --Wyrd Sisters