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I am getting this message when trying to log in: Sending of username did not succeed. Mail server mail.comcast.net responded: Plaintext authentication disallow

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  • Last reply by Pauldt

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I attempted to log in this morning and the system prompted me to enter my Comcast email account password. I am positive I am entering it in correctly. Then, this message pops up:

Sending of username did not succeed. Mail server mail.comcast.net responded: Plaintext authentication disallowed on non-secure (SSL/TLS) connections.

How do I resolve this?

I attempted to log in this morning and the system prompted me to enter my Comcast email account password. I am positive I am entering it in correctly. Then, this message pops up: Sending of username did not succeed. Mail server mail.comcast.net responded: Plaintext authentication disallowed on non-secure (SSL/TLS) connections. How do I resolve this?

Chosen solution

I contacted Comcast directly and found the solution. They recently changed their settings. To correct the problem, go to Thunderbird's Server Settings and change the Port from 110 to 995. Change the Security Settings on the Connection Security to SSL/TLS. Problem solved.

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In Thunderbird

  • Help > Troubleshooting Information
  • click on 'copy text to clipboard' button
  • In this forum question, right click in a 'post a Reply' text box and select 'Paste'.
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Chosen Solution

I contacted Comcast directly and found the solution. They recently changed their settings. To correct the problem, go to Thunderbird's Server Settings and change the Port from 110 to 995. Change the Security Settings on the Connection Security to SSL/TLS. Problem solved.