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Can't reply to thread in Thunderbird mac, says authentication failed but not true

  • 2 replies
  • 1 has this problem
  • 4 views
  • Last reply by ohialani

ohialani
ohialani
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This is regarding Thunderbird 78.10.0 (64-bit) in Mac OS 11.2.3 Big Sur. I've been having a very annoying problem in TB for months now when I reply to an email that I originally sent, someone replied and I CANNOT write them back as this message shows up every time: ALERT An error occurred while sending mail. The mail server responded: 5.7.0 Authentication Required. Learn more at...

This happens for individual recipients and groups. The ONLY workaround I have found is to start a new email, copy the subject and paste, copy the contents and paste, but actually recently it DOES NOT let me do even that! I have to copy only parts at a time, going back and forth. Then I have to re-enter all of the recipients in one at a time, and sometimes it is a long list. So you can see this is very tedious and time consuming and extremely frustrating. Does anyone else have this problem? Does anyone have a solution? Many of my emails involve a dialog requiring back and forth conversation. Thank you so much for any tips! PS I have been using ethernet only sometimes lately, I just turned wifi on and my message sent but don't know if this is consistent, and still would like to be able to use TB properly without having to connect to WiFi.

This is regarding Thunderbird 78.10.0 (64-bit) in Mac OS 11.2.3 Big Sur. I've been having a very annoying problem in TB for months now when I reply to an email that I originally sent, someone replied and I CANNOT write them back as this message shows up every time: ALERT An error occurred while sending mail. The mail server responded: 5.7.0 Authentication Required. Learn more at... This happens for individual recipients and groups. The ONLY workaround I have found is to start a new email, copy the subject and paste, copy the contents and paste, but actually recently it DOES NOT let me do even that! I have to copy only parts at a time, going back and forth. Then I have to re-enter all of the recipients in one at a time, and sometimes it is a long list. So you can see this is very tedious and time consuming and extremely frustrating. Does anyone else have this problem? Does anyone have a solution? Many of my emails involve a dialog requiring back and forth conversation. Thank you so much for any tips! PS I have been using ethernet only sometimes lately, I just turned wifi on and my message sent but don't know if this is consistent, and still would like to be able to use TB properly without having to connect to WiFi.

Modified by ohialani

All Replies (2)

Matt
Matt
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  • Top 10 Contributor
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Go to account settings and scroll to the bottom of the list to outgoing server (SMTP) and locate the SMTP server that is set to use no authentication and either correct it or delete it.

ohialani
ohialani Question owner
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What should it be on? Re: Security and Athentication? I have and have had it on OAuth2, which used to work fine months ago. This is driving me nuts, can't send my replies and is huge hassle. Thanks for your suggestion and any future tips re: this.