Suddenly I have an Authentication issue.

[linkup]

Out of the blue three of my email accounts had the same error message. I am using Thunderbird for a client on a Win10Pro PC accessing email accounts on domains on my server. No problems until this morning, all of the accounts worked fine, i.e. 19 email accounts on 19 different domains. 16 are still fine, but 3 just began throwing a common error:

Sending of password for user XXXX did not succeed. Mail server XXXX responded: [AUTH] Authentication failed.

For most of the three, I had no security setting, password only. I changed them to SSL/TLS and that didn't make a difference.

Can't figure out why 3 of 19 email accounts would randomly give me the Authentication error. This is a WHM server.

Help please!

Lew

 

[kodeslogic]

Check if you can log in to https://server-ip/webmail with the same credential you are using in your email client, if those login credentials are not working even in the webmail interface then possibly you are using the wrong credentials.

Try resetting the password for those email accounts and check.

 

[cPRex]

Trying webmail directly, like @kodeslogic advised, is the easiest way to test the username and password. Can you do that and see if that gives you the same login error?

 

[linkup]

Thanks for the suggestions. I should mention something else. Because I get so much spam, I use a program called Mailwasher to pull all the mail headers so I can filter mails. I sent a test mail to the three accounts. All of the test mails showed up in Mailwasher, meaning Mailwasher has no problems with the names and passwords of the same emails. I also was able to use Webmail to access one of the emal accounts with no problem. What would be different between how Mailwasher accesses the mail vs. Thunderbird? As an aside, unless the accounts were hacked, I use auto-logon with the email accounts, so nothing changed there. Thanks guys!

 

[cPRex]

It's hard to say - the next thing to check would be the /var/log/maillog file to see if there are any authentication errors for those particular users.

 

[linkup]

Thanks, but I don't know how to do that. I looked through the email options on the dashboard and I only found the mails it had received and how they were processed. Don't know where or how to see the AUTH failures?

 

[cPRex]

That log file would need to be examined on the command line of the server. If that isn't something you're able to do, or not comfortable doing, you can always reach out to your hosting provider to have them help with that work.

 

[linkup]

That log file would need to be examined on the command line of the server. If that isn't something you're able to do, or not comfortable doing, you can always reach out to your hosting provider to have them help with that work.

Thanks, I run/own the server and am unable to get help from the host.

 

[rbairwell]

Thanks, I run/own the server and am unable to get help from the host.

Do you have a username for the server of "root": if you should have access to the root command line of the server ( as @cPRex said) which will help you investigate the log files - along with access to WHM on port 2087.

If you do not have a username of "root" (i.e. you only login to cPanel on port 2083 using something like "linkup"), then you should be able to contact your hosting provider who has access to the "root command line" to investigate.

If you do have root, I would suggest becoming friends with (or contracting out to/paying) somebody who is familiar with the Linux command line at a minimum (ideally with Linux server administration experience and even better with cPanel/WHM experience) as your server is unlikely to be secure.

All that said....

I don't think looking at the log files will particularly help anyway: The fact Mailwasher (which runs on your Windows machine and hence would rule out firewall connection issues) and Webmail both appear to work with the same login credentials indicates to me the problem is more localised with Thunderbird.

I'm making a couple of assumptions here, please let me know if these are correct or not:
* You are running Mailwasher on your PC and have it configured with the 3 accounts (all using the full email address of the accounts you are having trouble with) you are having trouble with: and it works.
* You have tried logging into webmail directly at either https://server-ip/webmail or https://example.com/webmail (example.com being your domain name) with the full email address/password of the 3 accounts: and it works
* The problem is receiving email

In Thunderbird, under Tools->Accounts Settings and selecting your account, does it should as "POP3 (keep mail on your computer)" or "IMAP (remote folders)"?
Does the incoming settings there look identical to those in Mailwasher? Try using the "Manual config" to reset your in Thunderbird and check the the following settings:

Username: <full email address>
Password: <the password for that email address, not your cPanel password>
Incoming server: For IMAP: mail.example.com port 993 , For POP3: mail.example.com port 995
Outgoing server: mail.example.com port 465

If that's all correct, just try going to https://mail.example.com/webmail and logging in (again with the full email address) - does that work?

If after all that Thunderbird still isn't function, I would try a different email client (such as Mailbird or Windows Mail - on "Start" go to "Email and accounts"->Add an account->Advanced Set-up (not "Other account")->Internet email and enter the details as before ("Outgoing server requires authentication", "Use the same username and password for sending email", "Require SSL" for both. Does it work there? If so, there's an issue with Thunderbird and I would suggest a reinstall.