The something that has changed is not, I think, avast since this issue existed (and I tested it) 5 months ago.
I just found this posting in broadband reports:
This is a copy/paste from sympatico's forum:
The Incoming Server (SMTP) Settings need to be as follows:
Server Name: pophm.sympatico.ca
Port: 995
Check "Use name and Password"
User Name: youremail@sympatico.ca
Use secure connection: TLS
The Outgoing Server (SMTP) Settings need to be as follows:
Server Name: smtphm.sympatico.ca
Port: 25
Check "Use name and Password"
User Name: youremail@sympatico.ca
Use secure connection: TLS
Also, as Glen1 mentioned, turn off any email protection you may have in any anti-virus app you have, most email scanners won't work with ssl (encrypted) email. This will cause issues.
Also, I have heard smtphm port will use port 587 as well as port 25. Though i never tried it.
Yes, it is true that port 25 is the standard smtp port but there is no law that says an isp cannot choose to use it for secure SMTP and we also see it being done in the thread I linked.
Are you using port 995 on the incoming (POP3) side for your account in OE?
It may well be worth checking to see if mail is successfully delivered if the SMTP port is set for the account in OE to 587 which is now a well known port for secure mail sending (we have seen at least one other case in the forum where the secure SMTP traffic could be sent on port 25 or 587).
Remember that mail received or sent on a secure mail connection cannot be scanned by the Internet Mail scanner so you would be relying on scanning provided by the isp. To scan on the receive and send side by the avast Internet Mail scanner would require the use of STunnel. There will be no issues with it if port 587 can be used for sending your sympatico mail.
The only complication that might arise would be a problem of multiple email accounts where one wanted to send standard SMTP on port 25 and another account wanted to send secure SMTP also on port 25.
[Edited] to correct port number typo error.