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I can't send email

  • 4 replies
  • 0 have this problem
  • 2 views
  • Last reply by sfhowes

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I've been using Thunderbird with this same email info and settings for years with no problems. Suddenly today I couldn't send emails on any of the accounts, I can receive them. I've checked the settings to confirm but nothing has changed yet I keep getting the same error message. I checked with the ISP and everything was ok there, I could send and receive email on my phone. The computer was on and Thunderbird was open so there were no new updates recently that would have effected anything. I did try restarting Thunderbird and later the computer but the problem persists. Thunderbird version is 115.4.1 (32-bit) updated on 10/26/23 (about 1 week ago). I'll attach a screenshot of the error message. Any help is greatly appreciated.

Text of error message: Sending of the message failed. An error occurred while sending mail. The mail server responded: <kamdad@roadrunner.com> sender rejected. The email address you are sending as must match the email address you used to auth. Please check your SMTP settings. AUP#Out-1500. Please verify that your email address is correct in your account settings and try again.

I've been using Thunderbird with this same email info and settings for years with no problems. Suddenly today I couldn't send emails on any of the accounts, I can receive them. I've checked the settings to confirm but nothing has changed yet I keep getting the same error message. I checked with the ISP and everything was ok there, I could send and receive email on my phone. The computer was on and Thunderbird was open so there were no new updates recently that would have effected anything. I did try restarting Thunderbird and later the computer but the problem persists. Thunderbird version is 115.4.1 (32-bit) updated on 10/26/23 (about 1 week ago). I'll attach a screenshot of the error message. Any help is greatly appreciated. Text of error message: Sending of the message failed. An error occurred while sending mail. The mail server responded: <kamdad@roadrunner.com> sender rejected. The email address you are sending as must match the email address you used to auth. Please check your SMTP settings. AUP#Out-1500. Please verify that your email address is correct in your account settings and try again.
Attached screenshots

All Replies (4)

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The error suggests you're sending from account A through the smtp server of account B, so there is a mismatch between the User Names used for authentication. For each account, there must be a separate smtp server, and each account must be sending through the correct smtp.

https://support.mozilla.org/en-US/questions/1350593

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kamdad, how did you resolve this?

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I still have the problem. I tried installing Thunderbird on a different computer with the settings from my ISP (Spectrum) and it has the same problem, this suggest the problem is with Spectrum but they say its not.

I'm using gmail for now if I can't get it fixed I'll have to switch to outlook.
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The recommended Spectrum settings are:

incoming IMAP: mail.twc.com, 995, SSL/TLS, normal password, User Name = email address

outgoing SMTP: mail.twc.com, 587, STARTTLS, normal password, User Name = email address

https://www.spectrum.net/support/internet/mobile-email-setup

Your server name might be different, depending on the email domain, but the other settings are the same for all Spectrum users.