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Thunderbird Suddenly Won't Send Emails

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  • Last reply by SiGraybeard

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Thunderbird 102.10.1 (32-bit) Windows 10

On Wednesday afternoon, a couple of hours after the last email I sent, Thunderbird suddenly started bouncing my emails, with an error message saying "The email server responded <my email address> sender rejected. The email address you are sending as must match the email address you used to auth." I haven't touched those settings since I installed Thunderbird on this PC back in 2019. I've been running Thunderbird as far back as I can recall, probably as long as it has existed.

Image 1, SceenShot-bounce.

I have two email addresses with this provider (Spectrum Internet) a main address and a much less heavily-used alternate. The alternate works. Their SMTP settings are identical.

Thinking it could be my ISP or it could be Thunderbird, I've tried several tests, up to changing my password at my ISP. Nothing has resolved it.

Image 2, Screenshot-bounce2-settings is the two accounts side by side.

Thunderbird 102.10.1 (32-bit) Windows 10 On Wednesday afternoon, a couple of hours after the last email I sent, Thunderbird suddenly started bouncing my emails, with an error message saying "The email server responded <my email address> sender rejected. The email address you are sending as must match the email address you used to auth." I haven't touched those settings since I installed Thunderbird on this PC back in 2019. I've been running Thunderbird as far back as I can recall, probably as long as it has existed. Image 1, SceenShot-bounce. I have two email addresses with this provider (Spectrum Internet) a main address and a much less heavily-used alternate. The alternate works. Their SMTP settings are identical. Thinking it could be my ISP or it could be Thunderbird, I've tried several tests, up to changing my password at my ISP. Nothing has resolved it. Image 2, Screenshot-bounce2-settings is the two accounts side by side.
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"The email address you are sending as must match the email address you used to auth."

This suggests you have the two accounts sending on the same smtp. You should have separate smtp servers for each account.

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

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I don't understand. That linked Question you posted wasn't my issue. It didn't change my SMTP server's name or my name and I didn't change anything. Thunderbird just stopped working.

My ISP provides that SMTP server to use. I do have two accounts with them, but I've been using TB as is for years. I successfully used it to send email a couple of hours before this started and haven't been able to since.

The error message is false. That '"The email address you are sending as must match the email address you used to auth." The email address is the one I used to set up the account and has been my address since about 1998.