Outlook email client issues (isp Brightridge)

[tnhwyman]

Greetings,

I used to have Comcast/Xfinity internet cable service and switched over to Brightridge Broadband internet service a couple of weeks ago. Brightridge does not provide their customers with email accounts, therefore my wife and I still use our previous email accounts at Comcast/Xfinity. We were advised when we discontinued the Comcast/Xfinity service that we would still have access to our email accounts as long as we used them at least once every thirty days. I don't care much for the Microsoft Outlook client, and most times I access through any giver web browser, but my wife on the other hand is lost without her beloved Outlook client. I can understand her need, knowing this was what she grew up with in a thirty seven year corporate career job behind a keyboard. I have been on the phone support with Comcast/Xfinity and go around in circles trying to resolve the following issue, but each phone call takes me down the same path.

* All outgoing smtp.comcast.net port 587 fails with the following; "The server responded 421 resomta-po-17v.sys.co" error. I thought maybe it was our Wi-Fi router, but I hardwired her laptop and the results were the same. I took her laptop to an area coffee house to use a different isp and her outgoing email works fine. This leads we to think it is a Brightridge issue, but I don't know for sure. We are new to Broadband, and still on a learning curve so to say.

* Incoming mail imap.comcast.net port 993 works just fine.

She says her gmail account is not working as well, but I haven't made it that far yet, since Comcast is her default email account.

I have a domain, and thought I would test Outlook there to see what results I might come up with. I was able to both send and receive email without issue, so I am at a lose what the problem is at this point.

I bought my own router this week and have plans to give Brightridge's WiFi router back Monday 3/22/2021. I will try and see if they have any solution to offer us while there.

Thank you for any help advice on this problem.

[Philip]

Many residential ISPs block outgoing mail ports when you are not using their own mail servers. The idea is to prevent you from running your own domain/spam campaign from your own computer. This is likely the culprit, as you are trying to send out email using some other domain (Comcast) on the Brightridge network.

I would try alternate outgoing mail (SMTP) port numbers. For example, SMTP outgoing port 25 (or 587) is usually blocked by ISPs, but alternate port 2525 usually works.
Apparently port 587 (SMTP) is blocked, but port 465 (SMTPS) may not be?
Ideally, you could ask Comcast what alternate SMTP ports can be used with their mail servers.

Another approach would be to try change the outgoing server encryption type (in the Advanced settings tab) from TLS/SSL to STARTTLS

I hope this helps