I changed my Xfinity passwords. Now all apple email accounts wont send through SMTP. Need help.

On the Mac, go to Mail > Settings > Accounts > [choose account], then select the Server Settings tab. In the Outgoing Mail Server section it will show your Account and probably show that it is offline. Select that dropdown and choose Edit SMTP Service List on the bottom. With the same account selected in the top part of that screen enter the new password in the Password field.

Tesserax,

I had experienced the same problem as P D and may be able to provide a little more context. Hopefully P D will chime in as well and try your suggestions for a more specific solution.

• It only affected Xfinity accounts, all others worked fine.
• Only a problem on the Mac as P D said sending mail worked fine on their iPhone
• Using Connection Doctor on the Mail app showed "Invalid Username or Password"
• The server would go online/offline on its own without making any changes. This would be confirmed using Connection Doctor with all accounts showing green and also by being able to successfully send mail.
• I found files in the Keychain app titled "com.apple.account.SMTP.password" and "smtp.comcast.net" that contained the old Xfinity password, so I replaced the password there with the new password. After that everything has been working for me, but not convinced that it was the solution and could be that Xfinity just solved the issue on their backend at the same time.
• After I changed the Xfinity password on their website, Mac Mail asked for the new password as expected and gave no additional errors. The problem was only noticed when attempting to send mail as receiving was no problem. I then went to Mail Settings and the SMTP Server Settings to verify if the password was updated there as well as the Incoming Mail Server, but unable to confirm if the password was updated since is just shows "xxxxxx" and the number of digits in my new password was the same. I put my new password in there just in case it had not been update.
• I tried both ports 465 and 587 with no difference and made sure the SSL/TLS box was checked.

In any case, for me everything has been working fine and not sure if it was anything I did or just the SMTP server working correctly now on the Xfinity side. Hopefully you will be able to help P D resolve the issue they are having.

Did you replace the password in both the incoming mail server and the outgoing mail server(SMTP). There are 2 locations that the same password will need to be provided.

On your Mac, you can go to Mail > Window > Connection Doctor, and it will tell you if the password is correct for the SMTP server.

P D wrote:

Hi Mac Jim ID,

Thanks for the responses.

Yes, I've set the same password in both the incoming and outgoing servers sections of the email accounts dialog and also in the drop down Account window in outgoing. No luck.

I was hoping the Activity Log might give specific clues. Any thoughts there?

Peter

Another user earlier today resolved the issue by changing their Xfinity password again. Not sure why it worked, but it did in their case. A lot of us are having to change our password due to the security breach and it seams the volume is too much for their mail servers to keep up.

Can't access Comcast email since password… - Apple Community

If that does not work, you may want to try removing the account and adding it back in. As long as your emails are on their servers, they will download again to your device. Also verify your new password was accepted on their end by logging into their web portal.

P D wrote:

Okay. Mac Jim ID. Good man. I think you figured it out.

I deleted all the password entries in the Keychain and, after a few hours, the fields where passwords are entered in Mail in the outgoing SMTP (edit SMTP server list) became grayed out as "optional". I reentered the passwords, and, yeah, outgoing seems to be working. At least for the moment. YES!

I'll update as time goes by if something changes, but as far as I'm concerned at the moment, you are a genius. Thanks for the tip.

Peter

Good to hear. I have not had any trouble all day after making that change. Wish I had a better explanation on why that was needed.

P D wrote:

Akk. Must be Xfinity then.

As I mentioned in the initial post, I'm able to send email from my iPhone if I turn off the WIFI option and it sends over cellular. That's not a complete solution, because it doesn't solve the more important problem of sending from my computer, but I am curious why that would work. Is there a different SMTP internal routing structure at Xfinity that handles emails being sent over cellular. Or what weird spooky magic might cause that?

Everything working now. I did make a change on my Mac, but do not know if that is what did it or this is just another sporadic connectivity issue that will go down again.

This is what I did:

• Opened Keychain Access
• Selected System Roots in the Sidebar
• Searched for "smtp.comcast.net"
• There were 2 sets of files that I changed which had my old password, so I changed it to the new one. The first set were named "com.apple.account.SMTP.password" and there were several there and I looked for my main Xfinity account email and double clicked it to enter the new password. I also did the same in the set of files titled "smtp.comcast.net". Again there were several there and I just changed my main Xfinity Email since it had the old password in there.

I do not know if these files are even used for authentication with Mail, but the fact it had the old password in there I figured it would not hurt to replace it with the new password. I am not 100% confident it solved the problem since it had been going offline/online all morning before I made the change. I will update if it goes down again.

Just to make sure I understand. Your post mentions that this issue is with your Xfinity Email accounts. How about any non-Xfinity accounts. Are they working properly?

If they are, and this is only limited to Xfinity, it is highly unlikely that this issue is solely the burden of your Apple Mail client. Otherwise, it would affect all outbound emails using SMTP.

Regardless, to test that, outside of the Mail app, we would use a simple command in the Terminal app to create a connection to an SMTP server.

The following is the command with the iCloud SMTP server:

• ncat -v -4 smtp.mail.me.com 587

A successful response would be something like:

• 220 iCloud SMTP - pv50p00im-ztdg10021201.me.com 3.8.1 (2404BSE10-22f14bb4ec75)

Failed responses could be:

• Connecting to servername.domain.com…Could not open connection to the host, on port [25 | 465 | 587]: Connect failed
  • The SMTP server is not configured to receive mail on this port.
  • The SMTP server is not running properly.
  • A network issue is preventing your email client from accessing the SMTP server.
    • Software or hardware firewall not properly configured
    • Misconfigured DNS servers
• Smtp.mail.me.com: nodename nor servname provided, or not known
  • DNS resolution failure
• Trying 17.142.163.8…
  • The port is being blocked by your ISP or by the email service provider.
    • Three potential solutions for port blocking 25 1) If your ISP is blocking port 25, the preferred solution is to use the outgoing mail server provided by your ISP, 2)Try reconfiguring your email client to use either port 465 or 587, or 3) Use the secure, or SSL, port for outgoing mail. This will involve selecting the setting "this server requires a secure connection (SSL)" in your email client. This change should only be necessary for the outgoing (SMTP) server.
  • The destination SMTP service is unavailable.
  • Restrictions on the destination firewall.
  • Restrictions on the source firewall.
  • Incorrect FQDN or IP address for the destination SMTP server.
  • Incorrect port number

To exit the ncat session, enter: <control><C>

And also to add the what you are experiencing, I just saw my Xfinity SMTP server go offline and running Connection Doctor is showed invalid password, but without doing anything it went back online. They are experiencing trouble on the back end, which is only making it more difficult for you to change your password.

tl:dr The issue appears to be related to too many authentication attempts to the eMail provider's SMTP servers.

The boring technical details:

Do you use a software firewall on your Mac? Did you configure any firewall rules on your local router? Other than changing your Xfinity password, did you make any other changes, update software, etc.?

The Xfinity data breach, and resultant rush to change password could very well be overwhelming the servers ... so waiting a day or two (I don't think you need to wait a whole week) would be a reasonable approach.

On your question about the "client," I am referring to the email client ... which, in this case is the Apple Mail app. What I see in the logs is that it creates a connection to the SMTP server, is authenticated by that server, but then quickly rejects the server's response and sends a command to terminate the connection.

The following image (I don't remember where I got it from originally) is a graphical depiction of the series of communications to establish (& terminate) a successful SMTP session. Sorry, it's a bit blurry. In the image, the SMTP Sender, in your case, is the Apple Mail app. The SMTP Receiver would be your Email provider's SMTP server.