What mail provider is refusing to send your mail out. (note Thunderbird places no limits on the number of people you send an email to.)

It is not my mail provider since I was able to respond with no issues using Eudora.

jdevlin said

It is not my mail provider since I was able to respond with no issues using Eudora.

Well what do you think the problem might be then? As it is not Thunderbird, it has no limits on the number of folk an email can be addressed to and it is not your mail provider on you assertion, where should we start looking do you think?

Who is your mail provider? I will assume Google for now. they limit your mail sending, jsut as most providers do. See this for information on limits imposed by some of the larger well known providers.

Your Internet service provider will also have limits and they will most likely by much tighter than those for Google et al.

I have done some more testing and I think I know what the issue but I don't know how to fix it.

When I reply all Thunderbird instead of making one CC: line with multiple emails separated by commas, It makes multiple CC: lines with one email each. I need to know how to make TB make one CC: reply all line.

So that still makes it a TB problem.

jdevlin said

I have done some more testing and I think I know what the issue but I don't know how to fix it. When I reply all Thunderbird instead of making one CC: line with multiple emails separated by commas, It makes multiple CC: lines with one email each. I need to know how to make TB make one CC: reply all line. So that still makes it a TB problem.

Makes no difference to how the email looks to the SMTP server. You are chasing a red herring.

Just save as an eml and open in a text editor to see that is does not make a difference.

All I know is it works in Eudora but not in TB. There has to be something about TB that is messing it up. That's why I come here for help.

Things like this and not being able to nest addresses in the address book is what keeps me using Eudora.

jdevlin said

All I know is it works in Eudora but not in TB.

So you have clicked reply all is exactly the same message in Eudora and it worked. Not that you could on some other message. This message!

There has to be something about TB that is messing it up. That's why I come here for help.

I would call it opinion shopping. You have already decided where the problem must be and are looking to things to support that view. I asked who your mail provider was. Got nothing. You might also try posting the error message verbatim. I am assuming the to many recipients message is accompanied by an error code. That is usually the mails server error code 452 or 4.5.3

I get lots of hits when I google "many recipients error" with many different mail clients, and none of the issues I see have anything to do with the mail clients.

I have seen error messages about exceeding sending limits when folk fave incorrectly set the SMTP server to not require authentication. But that is a sending limit, not to many recipients.

Things like this and not being able to nest addresses in the address book is what keeps me using Eudora.

The bug has been open 19 years.https://bugzilla.mozilla.org/show_bug.cgi?id=40301

But I really don't understand the fine differences here. because this bug allows lists within lists https://bugzilla.mozilla.org/show_bug.cgi?id=1287726 But there is discussion about it specifically not allowing lists within lists. So I just do not know. Not care really. I do not use mailing lists. I use address books.

Yes I am using Eudora and TB in parallel. I am trying to find an alternative to Eudora that works for me. So far TB is the best but it still has issues I don't like. My provider is bell.net

Yes I clicked reply all on the exact same message in Eudora after it failed in TB. Eudora sent the message no issues.

The error was copy and pasted verbatim. No error numbers just an OK button and yellow triangle with exclamation mark. That is why I was what configuration I need to adjust as the error message says.

I don't care about the mailing list thing now it's just another reason I have for not fully moving over to TB.