Yesterday, I found that I was suddenly unable to send e-mail through Outlook. If affects only my main comcast.net email on my desktop. Comcast says it's not their problem. I made NO changes to my account or Outlook profile. I run a Dell computer, Windows 10 Pro, Outlook 365, kept up to date.


1. When I send or reply to a message, it goes through the Outbox and ends up in the Sent Items folder, but the recipient never receives it.
2. If I send a message to myself, it ends up in the spam folder on the Comcast server (it should not do that--I have my own address added to my address book on the server).


2b. When I send a message to my desktop e-mail from my laptop, it does NOT go to the Spam folder--it is processed normally.
3. When I set up a profile for my desktop e-mail account on my laptop computer (also Outlook, but different version), I still have the problem.
4. However the problem does not exist if the do the reverse: either laptop profile on the desktop or desktop profile on the laptop.


I conclude from all of this that the problem exists with my desktop e-mail account, whether it is operated from my desktop or laptop computer, and that it is on the Comcast side, and Outlook is not at fault.
If I log into my desktop account on the Comcast server, I can send or reply to messages successfully from there. The problem occurs only when using either of my home (desktop or laptop) computers), and only when using the profile for my desktop account.
Comcast contends a recent update to Outlook is causing the problem. I don't see how, as my desktop installation of Outlook works fine as long as I'm logged into my laptop profile. They also said that since I have Outlook set up as my "primary e-mail" they are not responsible. I would have have to make Comcast as my "primary e-mail" instead. I don't have any idea what he was talking about.
I had this EXACT same problem back in early April. I fought with their tech support for a day and it resolved the next. I asked them to check their service record, and they show that they didn't do anything to resolve the issue--that it spontaneously resolved. I don't know if that's true (there are other explanations), but if so, this might go away in the morning.


Any help (or even commiseration) will be greatly appreciated!!