SMTP server configuration for Apple mail (and related issue)

I'm having a similar problem with Thunderbird using POP3. Just started a couple of days ago. I have 4 comcast.net email addresses and can receive mail for all 4. I'm able to send messages from only one.  That one is shown as the default outgoing server. If I try to send a message from any of the other 3 addresses, I get a sending of the message failed. The mail server responded: Please ensure your email address and authenticating user match when sending messages. Please verify that your email address is correct in your account settings and try again.

I tried adding @comcast.net to user names, adding outgoing servers that match various identities, etc. I then selected the outgoing server that matched the email address. Nothing worked.  Can still only send from one account. 

I'm able to send messages on all identities from the WEB page. I was also able to get the windows 10 mail app to work for all identities, but only after linking all identities and IMAP. 

I'd really like to continue to use POP3 on Thunderbird and hope to see a fix soon.

Does anyone from Comcast look at this Forum and does it happen that they act on it? Based on the two additional users experiencing the same, it looks like Comcast had to change something on their side. Since the problem seems to be on the outgoing side (SMTP server), I am surprised that it doesn't affect more people. Also not being a technical person, not knowing and understanding configurations, servers, etc. , I find it surprising that everything works well for webmail (through the browser) and also from an iphone. No issues there. It seems that Apple mail and Thunderbird are impacted and Comcast (browser based) or iphone email are not.

SOLUTION:  Log into Xfinity Mail via a desktop computer or a non-Apply smartphone or tablet.  Click settings (gear icon), choose Security, check the box that says authorize 3rd party applications.  The error messages on the iPhone will immediately disappear and your mail will sync up with the IMAP mail server if you're using that.  I just figured this out earlier today helping a relative get Xfinity mail on their new iPhone.

I appreciate it but this might be the solution for a different problem. As I mentioned, there is no problem with the iphone (zero error messages) and I am not using IMAP but POP3. I would not want to sync my devices, that's why I using POP and no IMAP.

Did you try and check the third party authorization box anyhow to see if it solves your issue?  Maybe it will.

Thanks Jennifer from Comcast. I will try what you suggested and see if that helps.

Yesterday I somehow managed to get past the Chat with the computer (I could not repeat the trick today) to chat with a person. He could not help but told me that someone will call. And someone did and I was lucky to be at home at that time. It was a first level technical staff who tried really hard to help. We spent 1.5 h on the phone but he could not do too much for the problem. He said that a next level technical person will contact me. He promised to open a record, give me and send me the record number and then we were disconnected. He never called me back, maybe he couldn't, I don't know and I never got the record number...  I wish Comcast had a tool like Apple, to watch one's screen, be on the phone and direct one but not be able to do anything on one's computer. I will try to send my info to Comcast as suggested and see what happens. With multiple people reporting the same issue that was just created by Comcast making some change, maybe they will fix the problem.

I am sorry Atlong. What you are referring to is webmail. On my computer under the gear icon I do NOT have an entry for security. Regardless, Webmail, as I mentioned, works with no issues.

Open webmail in a browser.  Click gear icon top right.  Select email settings.  This will bring up all of your email settings.  Third entry down on left side, you should see Security (between Accounts and Mail).  Click Security.  Look to the large pane on the right.  Find last entry and please select checkbox for 3rd Party Access Security.  If that doesn't fix things, I will yield to Xfinity to provide further support.

Thanks Atlong. I found Security. The option to allow 3rd parties WAS already checked off. I appreciate you trying to help, but unfortunately this is not the solution. Comcast changed something that their first level support people do not know about that created this problem.

user_7dce55, what email client are you using and what device type?

I followed Xfinity-Jennifer's suggestion and sent a text to her through Comcast's "direct messaging". She believes that the new issue impacts "only" Apple Mail users and that that's just a small subset of users. I suggested that she looks at Fleur101's post, who uses Thunderbird (another 3rd party email client) who reports the exact same issue. I am sure that there are many more users who are experiencing issues but they do not come to this forum. They try to Chat and call Comcast as I did. And since it is experienced by other users not only Apple Mail users, it is clear that it is not an Apple issue, (as also shown by the error message displayed by Apple and Thunderbird emails), it had to be created somehow by Comcast.  I am happy to help debug if I can, but the expectation is that Comcast will fix this problem, even if it impacts "only" Apple mail and Thunderbird users. Hopefully it will happen, showing that Comcast cares about its customers.

XfinityAaron, may I assume that this problem was formally reported by you or Jennifer to technical staff?I hope this was done, so at least they know that there is a problem.

In addition, could you please clarify when Comment is supposed to be used vs. Reply. What did those who designed this Forum envision about their usage, as I find it confusing? The only thing I know is that unfortunately if one uses Reply, no notification goes out that a Reply was posted. Otherwise, I do not understand the difference and purpose in life for the two different options. No other Forum that I use has something like this. Thanks.

I finally got Thunderbird working (POP3) for my 4 email addresses. Settings I used for years, stopped allowing me to send messages about a week ago. I loaded thunderbird on an old laptop, let it automatically do settings for POP3, and everything worked fine. I then compared all the settings and changed what was different and everything started working again. The difference was in the outgoing mail server. In the past, all 4 email addresses used the same default outgoing mail server. I had to add a separate outgoing server for each address. Thunderbird has a separate outgoing server entry button (bottom left pane) of settings which allows you to "add" a server. After adding 1 server for each identity, I had to go into each identity and select the server entry matching that identity in the right pane. I tried something like this earlier, but not in both panes.

I don't use a MAC or Iphone, but hope this helps the Apple users.

Judy

Fleur101, you are very brave and did a fantastic job. Congratulationas!!!    Hopefully Comcast will learn from it and help the rest of us.

All I know is that the POP3 protocol; is used for incoming mail (which works without problems) and SMTP is the protocol for outgoing mail, which has a problem, but luckily only for 1 of my 3 email addresses.

With Mac mail one has for the Outgoing Mail Server (for each email address):

- an "account" (which I really do not know how it was created, etc.)

- a user name= email address

- a password (supposedly the password associated with the user address) and

- a HOST NAME, which for all email addresses is smtp.comcast.net. 

I do not know which configuration options for Apple mail match what you described for Thunderbird and might need to changed to something else, but now with the info you provided hopefully Comcast will figure it out.

The "accounts" listed for the 3 email addresses are:

- email address #1 (the one that cannot send out emails): account = Comcast

- email address #2: account= Comcast

- email address #3: account= Comcast.net

When the error message is displayed by email #1 that cannot send out messages, a list of "accounts" (which appear to be the SMTP servers) is displayed with an option to Edit SMTP Server List or use Connection Doctor. The SMTP Server List has: Comcast, Comcast.net, Comcast.net, Comcast. net and Google (I also have a gmail email).

If one goes to Accounts (under Mail/Preferences, it shows entries for:

- description=Comcast; server name=smtp.comcast.net; in use by account email #1, email #2

- description= Comcast.net; server name= smtp.comcast.net

- description=Comcast; server name=smtp.comcast.net; in use by account email #3

I included this detail because every time I include a screen capture is removed because of private info...

Maybe with your skillful debugging and this info, Comcast can provide the needed help. Thanks for doing all the legwork and sharing the solution, Fleur101!

The out

going port used for ALL my email addresses is 465. I attached a screen capture showing what I see under Edit SMTP Server List for Outgoing Mail Server/Account (Comcast) for the Server setting for the problem email address - email #1. Please use COMMENT as REPLY does NOT sent a notification. Thanks.