All that does is specify which ports the Exim Daemon listens. That does not dictate what is shown in the Mail Client Configuration page which is not modifiable. The port 587 while usable with TLS using STARTTLS it is not a straight SSL port like 465 is and as such isn't shown for the Secure SSL/TLS Settings. This is detailed here:
These ports 465 and 587 are both used for sending mail (submitting mail) but what is the real difference between them?
Then something else must be going on, because a telnet to 465 (while it does accept the connection) does not produce a 220 or any other SMTP activity, and an EHLO does not give a response either, it just drops with any SMTP commands sent...
This was pointed ot me by a colleague, from just 7 days ago...
Choosing the right SMTP Server Port can be tricky. Learn with Pepipos the types of SMTP Ports and how can you choose the right one.
- SMTP port 587 is one of the best choices for nearly every use case for connecting to Pepipost
- Port 25 is the default port used for relaying
- Port 465 should no longer be used at all
- Port 2525 used when all other port is blocked
And this one is from 2015:
Configuring SMTP ports can be a difficult and confusing process. Learn how to set SMTP ports correctly with this helpful online guide today at JSCAPE.
To summarize, the recommendation is that:
- port 587 should only be used for submissions (i.e., mail client to mail server),
- port 25 should only be used for relaying (i.e., mail server to mail server communications), and
- port 465 should no longer be used at all.
Although not all email service providers adhere to these recommendations, these are idealisations that we should all be working to achieve in order to eliminate the confusion surrounding SMTP port configuration.
If 465 worked, i guess it wouldn't be an issue. But it's not, and I've scoured for something as to why in the settings. But if it's not even recommended to use, why would I?
I still am in need of a way to change what is displayed in the manual settings info though...