pop 110/995, imap 143/993 ?

[Sebastian Arcus]

On 21/08/17 00:28, voytek at sbt.net.au wrote:
> just setting a new Dovecot server to migrate from older system, but, I
> have a general question:
> 
> 1. I've set the server with self issued cert, and both pop/imap
> StartTLS/110/143 SSL/993/995 (apologies if I'm using wrong naming
> terminology)
> 
> is there a 'preferred way'?  should I tell users to use 143 over 993 ? or
> 993 over 143? or?

I believe the recommended way for years has been to use the 
encrypted/SSL versions of both IMAP and POP3 - so ports 993 and 995 
respectively. Otherwise you are effectively sending data in plain text 
over the internet.

> 
> my current understanding is that some (MS?) clients might not support
> StartTLS/143 ? so best to offer both ?

As far as I know, all popular email clients of the last 15 years, that I 
can think of, support POP3 on 995 and IMAP on 993 with SSL.
> 
> I think? some public WiFi block 993/995 but allow 143/110, hence, another
> advantage for using 143/110

I never heard about his, Maybe others have. I guess this would be even 
more of a reason to use the encrypted versions of the protocols.