Given the error message is for a server, are you saying you have multiple accounts with the one provider.

My guess is it would be for the mail account that is not updating with new mail.

Matt said

Given the error message is for a server, are you saying you have multiple accounts with the one provider. My guess is it would be for the mail account that is not updating with new mail.

No every account updates.

I have started to getting this problem today with Yahoo Imap server. It started to keep asking for my certificate and refusing to connect.

I checked the server settings for Yahoo which are fine and haven't been changed for a long time anyway.

Yea i tried to uninstall TB then remove the folder with the profiles and reinstalled again but no it didn't fix the problem.

What's wrong really this message is saying nothing. I tried lower every account to 1 server connections to cache but it didn't abbreviate the problem.

Hi klappa - if you also use Yahoo, like Ambroz, you may find this similar question has useful information. It might be that Yahoo has changed its requirements, and older settings no longer work. https://support.mozilla.org/en-US/questions/1272259 Note - this may not be a close match to the symptoms you are experiencing - just offered in case anything explored there seems worth trying for you. Toad-Hall's suggestions may help. This is the same issue, with helpful suggestions from a different forum https://helpforum.sky.com/t5/Email/Unable-to-connetc-to-IMAP-server-etc-on-Thunderbird/td-p/3099397

Then to trouble-shooting. The message you see about exceeding connections may be accurate - in which case see the earlier part of those discussions, regarding reducing the number of connections allowed in all of the devices you use to connect to your email server. Note that it might also be because you have multiple accounts connecting to the same email service simultaneously. However, it may be a message that is not accurately describing the real problem, in which case, reducing the allowed connections for each device won't work.

If you find out the solution please report back. Sometimes your experience can help others. Agnes

Thanks but that didn't work and yes it's Yahoo. I have no idea what they've changed. Yahoo doesn't work with Thunderbird anymore without throwing that IMAP error message at me and lowering maximum number of server connections to cache doesn't work either. I've tried everything!

Are you using oAuth authentication on your yahoo IMAP accounts? It is almost mandatory with them.

Matt said

Are you using oAuth authentication on your yahoo IMAP accounts? It is almost mandatory with them.

Of course. That's the first thing i checked but if it wasn't it would throw me a authentication error instead which it doesn't.

The error you are seeing indicates that the server has set a limit in the total amount of connections that you can make with your account (across all devices at that current time) and you have reached that limit.

It results in the exceeded max number of connections message that you are seeing.

Reduce the number of folders that you are synchonising. It can also help if you increase the checking for new mail interval to at least 10 minutes.

Set a lower threshold in Thunderbird for each mail account. Account Settings > Server Settings > 'Advanced' button Choose lower than 5 eg: 3 or even 1

Phones, ipad, any other computer etc: What other devices are connecting to that yahoo account? You may have another computer or email client still connecting or even a phone that has not disconnected from server.

Force closure of connections to reset everything: You need to exit Thunderbird and check phone is not connecting by switching off. Do you have a computer in a different location that is still connecting? There have been occasions when some people have a computer at home and another at work and one of them has been left on connecting to server.

On ce everything is switched off and not connecting, please wait for a good while as the server needs to reset things and it is not always as immediate as one would like.

Toad-Hall said

The error you are seeing indicates that the server has set a limit in the total amount of connections that you can make with your account (across all devices at that current time) and you have reached that limit. It results in the exceeded max number of connections message that you are seeing. Reduce the number of folders that you are synchonising. It can also help if you increase the checking for new mail interval to at least 10 minutes. Set a lower threshold in Thunderbird for each mail account. Account Settings > Server Settings > 'Advanced' button Choose lower than 5 eg: 3 or even 1 Phones, ipad, any other computer etc: What other devices are connecting to that yahoo account? You may have another computer or email client still connecting or even a phone that has not disconnected from server. Force closure of connections to reset everything: You need to exit Thunderbird and check phone is not connecting by switching off. Do you have a computer in a different location that is still connecting? There have been occasions when some people have a computer at home and another at work and one of them has been left on connecting to server. On ce everything is switched off and not connecting, please wait for a good while as the server needs to reset things and it is not always as immediate as one would like.

I appreciate your lengthy reply but I have already done all those things even before i created this topic. It still shows up.

I don't use Yahoo for handheld devices.

re :I don't use Yahoo for handheld devices. Confirm: you do not access your emails for that email address using handheld devices.

Also confirm you have never used Outlook email client to view emails for that email address. I have known a case where Outlook was running in the background unknown to the user.

Have you set check server to at least 10 minutes ? Have you closed Thunderbird down for at least 30 minutes or overnight?