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I had to reinstall Thunderbird on my Mac mini with Big Sur and when I try to set up the accounts, I get an error message that it is not connecting to the server. HELP!

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  • Last reply by bigbun

bigbun
bigbun
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I had to reinstall Thunderbird on my Mac mini with Big Sur and when I try to set up the accounts, I get an error message that it is not connecting to the server. HELP!

I have all the correct POP3 and SMTP settings, all the correct passwords and we have tried this multiple times, carefully entering everything so as to avoid typos, but each time, it says that it finds the account, but then gives an error message that it can't find the server. Our ISP will not help with Thunderbird at all.

I had to reinstall Thunderbird on my Mac mini with Big Sur and when I try to set up the accounts, I get an error message that it is not connecting to the server. HELP! I have all the correct POP3 and SMTP settings, all the correct passwords and we have tried this multiple times, carefully entering everything so as to avoid typos, but each time, it says that it finds the account, but then gives an error message that it can't find the server. Our ISP will not help with Thunderbird at all.

Chosen solution

I realize you installed the latest version, 78, but was the previous version 68 or 78? There were changes in 78 that make it unable to connect to servers that don't support an updated version of TLS (security).

RCN settings for POP/SMTP are pop.rcn.com on 995, SSL/TLS, smtp.rcn.com on 587, STARTTLS; User Name = email address, authentication = normal password.

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All Replies (6)

sfhowes
sfhowes
  • Top 10 Contributor
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In Preferences/General/Network & Disk Space, Connection Settings, try 'no proxy', restart TB, and see if the connection succeeds.

https://support.mozilla.org/en-US/questions/1306336

bigbun
bigbun Question owner
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Got the same error message after trying this. Unable to log in at server. Any other thoughts?

sfhowes
sfhowes
  • Top 10 Contributor
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What is the exact error message? Post a screenshot if possible. When you reinstalled, did you change TB versions? Who is the mail provider, and what are your settings?

bigbun
bigbun Question owner
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The error message is that it is unable to log in at server. Because of what happened with the computer, we were forced to install Thunderbird again and I presume it was the newest version because they probably wouldn't put older versions on line for general use. At the time it was installed, there was no other version on the machine. ISP is RCN. Settings for POP3 and SMTP.

sfhowes
sfhowes
  • Top 10 Contributor
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Chosen Solution

I realize you installed the latest version, 78, but was the previous version 68 or 78? There were changes in 78 that make it unable to connect to servers that don't support an updated version of TLS (security).

RCN settings for POP/SMTP are pop.rcn.com on 995, SSL/TLS, smtp.rcn.com on 587, STARTTLS; User Name = email address, authentication = normal password.

bigbun
bigbun Question owner
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sfhowes:

Thank you, Thank you, Thank you!!! Solved my problem. I uninstalled the newer version, installed a 68.x version, and I'm up and running. :-)