I-Thunderbird Community Forum

Here is the message I get. Very inconvenient... Sending of the message failed. An error occurred while sending mail. The mail server responded: Too many recipients. Please reduce the number of recipients and try again. AUP#Out-1550. Please check the message recipient "........" and try again.

I have two Charter/Spectrum email accounts (domain is charter.net) set up via IMAP in Thunderbird (latest version) on Windows 11 Pro (also latest version, August 2026 CU is installed). They no longer update; at the moment I see no email in either after 8/27/26 around 5:00pm EDT. Confirmed via Web access there are emails after this point (a couple dozen at least, in each account).

Most recently I've tried repairing the Inbox mailbox for both. No help. Because I did that, Thunderbird now shows no emails in my Inbox even though it'd had hundreds of them before.

Note, I'd noticed the same problem a week ago, had tried fixing it at that time by removing both accounts and adding them back. They worked for a few days but then stopped working again on 8/27 as noted above.

Another oddity: If I go onto synchronization settings (right-click on account name then Subscribe), it shows no folders available to subscribe to. The folder list is empty and the Refresh button is grayed out. It shows it looked up and connected to mobile.charter.net at the bottom of the dialog, so I'd expect it would have retrieved the list of IMAP folders, but apparently it got nothing. And it refuses to get anything.

I assume I can remove the accounts and add them back, but why should this be necessary every few days? Seems bizarre. Thunderbird used to work with these accounts very well but now it seems to have blown up. Who decided this is how IMAP works?

I'm running Thunderbird 154.0 setup with my primary gmail account. If I add a second gmail account and receive email from there, when I reply to that will my response appear to be from my primary or the new, second gmail account?

I finally got Thunderbird to not go to Rogers every time I get email. But now I cannot send any email from any address.When I try to send I get an error message. I cannot add an SMPT server as it will not take it

After returning from a 6 day vacation, my wife attempted to download email from her Yahoo email account. There are nearly 200 messages that have piled up but they aren't moving. I've uninstalled and re-installed TB. I've uninstalled and reinstalled the app password in Yahoo. There is no problem with accessing the email via any web browser. I spent 49 minutes on a tech support call with Yahoo and they have said the problem is with TB because they repeated the same steps I have. I checked firewall settings and the only antivirus program on the computer is Malware Bytes and it's not running in the background.

The version of TB is the most recent as of yesterday. I don't see any sketchy looking emails in the web version of Yahoo Mail when it's opened. It's set up as a POP3 account and has been since Cox Internet gave their email over to Yahoo. I'd appreciate any assistance in resolving this because it's currently above my pay grade and tech support at Yahoo.

I had to recently change my password on my shaw email account. Now thunderbird won't download my emails. I changed the password in the account settings to match the shaw email account password but I keep getting an error message: "Host contacted, sending login information..." and then after a long delay the error message reads "Login to server pop.shaw.ca with username ... failed". Any idea what I'm doing wrong by simply changing the password? I think this happened before and some wonderful human on this forum told me I had to put something before the password or click/unclick a particular box, but I can't find that old answer to my previous question. Thanks in advance for any help someone can offer!

Hello,

I have been using Thunderbird for years without issue, but three days ago, I started having issues.

Now, I don't receive emails when I open Thunderbird. If I delete my password and re-sign in, I receive emails, but cannot send them. Trying to send an email makes Thunderbird ask me to sign in again.

I have two email accounts that I use with Thunderbird. Both accounts have this issue. I have this issue regardless of the network I'm in (work, cell hotspot, or home).

Things I have tried:

• Verified that my IMAP and SMTP settings match the guidance from email servers.
• Verified that my computer firewall is not blocking email.
• Tried connecting on different networks (so different ISPs)
• Deleted and re-entered passwords for each account

Here my current server configuration:

• Email 1 (@gmail.com)

 * Server Name: imap.gmail.com
 * Port: 993
 * Connection Security: SSL/TLS
 * Authentication Method: OAuth2

• Email 1 Outgoing Server:

 * Server Name: smpt.gmail.com
 * Port: 465
 * Authentication Method: OAuth2
 * Connection Security SSL/TLS

• Email 2 (@[university].edu)

 * Server Name: outlook.office365.com
 * Port: 993
 * Connection Security: SSL/TLS
 * Authentication Method: OAuth2

• Email 2 Outgoing Server:

 * Server Name: smtp.office365.com
 * Port: 587
 * Authentication Method: OAuth2
 * Connection Security SSL/TLS

I will greatly appreciate any help you can provide!

This is the message I get when I try to send a message. Sending of the message failed. An error occurred while sending mail. The mail server responded: <budguinn@charter.net> sender rejected. Please verify that your email address is correct in your account settings and try again.

I have included a screen shot of my server settings.

With the new meadow update when either replying to a message or selecting new message there is no command menu bar to send save as draft etc.... tried several of the commands an setting changes but nothing seems to work - can do cntrl+enter to send and that s about it....

I have been using Thunderbird successfully for sometime and since yesterday there were no new emails in my inbox. This coincided with Thunderbird being upgraded, so I am told. So, I tested by sending an email to myself but TB kept assuming my old email address was valid (died last year) and any attempt to get in and edit my address failed because it kept thinking the old email was was still valid. So, I installed Betterbird, hoping it might work but it copied over my profile, etc and it had the same problem! I guess I could look far another email client but I want to stay with Thunderbird.

Any suggestions please. Robin

Hi - Thunderbird has not fetched any emails from the past two days. I am running 153.1.0esr (64-bit) on Windows 10. If I remember correctly, I downloaded that version four days ago. I vaguely recall getting some message somehow that I needed the ESR. (Sorry I don't have a very good memory!) Thunderbird did fetch emails for two days after that...but I suppose it's possible that I didn't restart Tbird right away, so maybe it was still using an older version until two days ago?? My ISP is RCN/Astound. Last week, I changed my password on both the RCN webmail and on Thunderbird, and I could send and receive after that. Tonight, when I discovered that Thunderbird wasn't fetching, I also tried to send an email, but I initially received an error message. It was something like "Your message was unable to be saved" and then there was something about saving it as a draft. I've seen that message many times over the years, but I don't remember exactly what it said. Thinking it might be a password requirements issue, I changed my password again. I don't know if that mattered, but I am now able to send emails -- but I still can't fetch them. I turned off my Windows firewall and Windows real-time threat protection. That didn't help. I saw this thread https://support.mozilla.org/en-US/questions/1531863 tonight and set "network.dns.disableIPv6" to "true." That didn't help either. I would appreciate any assistance you can provide. Though I am not a expert, I am happy to provide more info if needed. Thank you in advance for your help.

How do I configure my thunderbird client to send e mail using my gmail account. Gmail's "solutions" do not seem to work - see attached for what they claim. I have used both ports 465 and 587 and the appropriate connection security.

Hi, We have suddenly stopped receiving emails from our booking provider, 'Inn Style' since the 13th August. All other emails appear to be being received. I have contacted our booking provider and it shows at their end that they are being delivered to us so have suggested it is a problem from the email provider. It is a big problem for us not receiving emails from our booking provider. Thank you for your help, Lucy

Hello. I have been unable to send email from one of several POP accounts on Thunderbird (v 115.18.0). I believe this occurred after Network Solutions changed the SMTP server for that email account. I am able to send email from my Gmail IMAP account setup on the same Thunderbird program on my PC. I have tried all the port and authentication settings for SLS/TLS and STARTTLS, changed/updated passwords, etc. I do not get any error messages, just never receive the test email I send to my other accounts. I updated the SMTP server on my iPhone mail app to the new NetSol SMTP and it works on that platform. I just cannot get it to work on Thunderbird on my PC. NetSol support said to delete account and start over which is not possible as it is my business email account. Also, the inbox is too large to back-up to an external drive. Any suggestions? Thanks in advance. John

I upgraded my 2012 macbook pro to the latest version of thunderbird and I can not get my emails. I am running os10.15.8 Every time I try to get messages a yahoo page opens up and wants me to sign into my yahoo account. I can't get rid of the yahoo page it just keeps reopening again and again. Everything was working fine until I upgraded thunderbird to 153.0.3esr. My other mac that has not been upgraded can still get my emails.

Is it possible to go back to the prior versions of thunderbird or make this new version work with my mac?