Can't connect iphones nor Outlook

I just looked and the box is checked.

@user_9m28m3 thank you for taking the time to confirm the box is checked. I want to make sure we aren't overlooking in the client set up. When you went to set up the new client, are the settings and ports matched to these: 

- https://www.xfinity.com/support/articles/email-client-programs-with-xfinity-email

- https://www.xfinity.com/support/articles/update-your-xfinity-email-settings

My systems problem has been corrected.  What solved the problem was unchecking the  the share box, then rechecking it.  My Norton prompted me if this was allowed, I said yes, not all seems to work!  Only took a week!

I apologize for the long post. For over a week I have been battling with my Comcast email.  It began with a request by Comcast for a password change.  I made that change but could not get my Outlook and 2 iPhones to link up.  Regarding Outlook, I repeatedly received the enter credentials box.  The cell phones said account unavailable.  I changed passwords several more times and the result was the same.  I deleted and recreated the accounts several times.

I have no VPN, the common cause of the Outlook problem.

I confirmed that the “allow third party ..” box was checked on my comcast settings and it was.

Over the whole event, my phones would send email but not receive.

Yesterday, late afternoon I tried something different.  I unchecked the “allow third party” box on Comcast.  Shut down.  Reopened and then checked the box.  Bingo!  Outlook began downloading hundreds of emails.  Finally, I had it figured out!  I then reset the phones and same thing happened, both downloaded all the emails.  Because Outlook had to rebuild my inbox, sent items, and trash folders, it was taking a long time.  Using Task Manager,  I monitored my file downloads and it was working at over 32 MPS.  I stepped away from the computer for dinner.

After dinner, I found the awful “input credentials prompt” once again on my computer and found I was disconnected.  Also, the two phones said “account unavailable.”  Back where I was before!  My Outlook files had been mostly recreated, but not finished.

Because all three sources were working, then stopped, I believe this must be an issue at the settings at the Comcast end, and why would they all work for several minutes then stop?  My email box is allowed 10G and it shows I am at 8.5G

@user_9m28m3 thank you for taking the time to follow up, and sorry to hear the issue has comeback after the email connecting and starting to sync. We definitely appreicate you trying the previous steps, and the update of the unchecking and checking 3rd party access. 

With the issue still persisting I'd like to look into this further, when you have time can you send a direct message. 

To send a direct message: 

Click "Sign In" if necessary

• Click the "Direct Message" icon in the upper right - it looks like a chat bubble  

• Click the "New message" (pencil and paper) icon just to the right of Conversations

• Type "Xfinity Support" in the "To:" line - do not use the Employee's name!

• Type your message in the text area near the bottom of the window

• Press Enter to send it

To expedite your request, we ask that you please include your name, the account holder name (if different), and the service address.