Sending from account different from SMTP server failing

[i_am_jim]

For years I have used this system. A few days ago it quit working.

I have a webhost which allows me many email addresses. My ISP is Comcast. I send mail using addresses on my webhost via the Comcast SMTP. I have changed nothing but a few days ago it quit working. Now all outgoing mail using the Comcast server fails with this message : https://photos.google.com/album/AF1QipN ... oBaqfe2yHj:

[DanRaisch]

That link is bad, comes up with a 404 error.
http://kb.mozillazine.org/Posting_a_scr ... _the_forum

[i_am_jim]

That's the problem when the forum software does not provide for images.

[i_am_jim]

Okay, try This One

[sfhowes]

Maybe the Comcast smtp no longer allows sending with non-Comcast addresses unless they are added to the Comcast account as 'allowed senders'.

[i_am_jim]

Comcast does not have a problem with my arrangement

[i_am_jim]

I take it from the lack of other replies no one here knows how to fix this

[i_am_jim]

I notice TB was updated recently, could this be the problem?

[sfhowes]

Asking the obvious: do you have the correct settings for the Comcast smtp? smtp.comcast.net on port 587, STARTTLS security, or port 465, SSL/TLS security. Authentication = normal password, User name = email address.

https://www.xfinity.com/support/article ... nity-email

https://www.xfinity.com/support/article ... hunderbird

[i_am_jim]

When I said above "Comcast does not have a problem with my arrangement" it meant I called comcast and read them my setting and they said they were correct and could help no further.