Do you really mean "profile" or just "email address"?

Under these circumstances, I'd expect and hope for Thunderbird to use the default address.

If you mean "profile" then it would usually use the one it was using last time Thunderbird was running.

Not sure I understand the question. The Thunderbird "write" window that opens when I click on a mailto: link in Firefox shows in the "From" field the address and after that in italics and grayed out the account name other than the account name that I want. From that I infer it is using the unwanted profile. But it is definitely not the last-used profile. I use Profile #1 several times a day, and I created Profile #2 a week ago as a test but haven't used it since then. I would like to declare Profile #1 to be the default profile to use for "mailto:". (I don't know if it matters, but Profile #1 is POP and P #2 is IMAP. And the user names under Server Settings are not the same.)

Can we change the language, this is incredibly confusing to read.

You are referring to an account as something else that Thunderbird does. Profiles. A profile is a complete change to everything about Thunderbird, just as if it were installed on a different machine. Different address books, mail account RSS feeds and news servers.

So using your statement that you click the mail to link, and assuming Thunderbird is closed when you do this (otherwise mail to will use the currently selected mail account in the folder pane.)

Right click your mail account in the folder pane. Select settings Scroll the account settings dialog list right to the bottom and select outgoing server (smtp) Select the account you want as default. Click the default button.

I tried the solution above, and it has not resolved the issue. In fact, I deleted the unwanted profile via TBird profile manager as well and deleted the profile folder and its subfolders. But when I click on a mailto: link in Firefox, something appears to re-create the profile folder and use it. I suspect the problem may lie within the Firefox options and not solely within TBird, but I can't find where the erroneous profile-pointer is stored. I tried searching About:config in Firefox, but nothing useful appeared. As I said up there a ways, I would like to declare Profile #1 to be the default profile to use for "mailto:". But I can't find out how to do that.

@[ronks]

If the above information does not resolve your issue, please consider creating a new thread containing the specific details of your issue.

Doing so will allow the Mozilla volunteers to give you solutions that are more helpful to you. This may help them to solve your problem faster and more efficiently.

Please, feel free to post the link to your thread on this thread for volunteers interested in assisting you.

Thank you.

I am not sure what more information I can provide. The question in the initial post is still about all I know to say. I could start another thread which repeats it, if that is the custom here.

A profile can contain many email accounts. So selecting a profile doesn't determine which account or identity will be used when creating a message (unless the selected profile contains only one account).

Users who insist on using separate profiles usually either select at runtime via the profile manager incorporated into Thunderbird, or they set up shortcuts or batch files to use the command line to run a specific instance of Thunderbird with a named profile. I don't think the "mailto:" protocol has support for any of these subtleties. The remaining possibility is to use an add-on which allows you to swap between profiles within Thunderbird, but I can't see how that would be attractive in this context.

https://support.mozilla.org/en-US/kb/using-multiple-profiles http://kb.mozillazine.org/Starting_your_Mozilla_application_with_a_specified_profile

If you can subvert whatever is launched by clicking on a "mailto:" link to make it run or call another program, then you can use this to run a batch file which would invoke Thunderbird with a specific profile, or even more directly, you could launch Thunderbird with a set of command line parameters which fill in parts of the message - to:, subject, attachments etc.

http://kb.mozillazine.org/Command_line_arguments_-_Thunderbird

Note that the preselectid term would let you select the account/identity to be used to send the message.

Just to recap. You said:

"I don't know if it matters, but Profile #1 is POP and P #2 is IMAP. And the user names under Server Settings are not the same."

where you're actually describing accounts, and you also said:

"I deleted the unwanted profile via TBird profile manager"

showing that you are confused about the meaning of "profile", or at least being very unclear about your actions.

You are deleting accounts or deleting profiles or possibly both, but we can't tell which due to your ambiguous usage of the terminology.

I would appreciate a pointer to a definition of the two and the distinction between them.

Or to state the issue a different way: When I click on a mailto: link, Thunderbird opens a window to compose a message. After my From: address is a character string in italics and gray letters. What does that character string represent?

And surely the Profile Manager deletes profiles? If not, it is badly misnamed.

This article talks about profiles.

https://support.mozilla.org/en-US/kb/profiles-tb

It's not crystal clear, but in referring to "user preferences" the article is telling you that account settings are stored in the profile. So a profile contains accounts. When you discuss POP vs IMAP, these are accounts. As far as I understand it, you want to control which account is used when you click a mailto: link. I think you have two options:

1. set up Thunderbird with only one account, then that is the only account that can be used
2. craft some way of launching Thunderbird via a carefully constructed command line with arguments that tell it which profile and which account to use

A possible variation on these would be to set up a default Thunderbird with just the one preferred account, and the mailto: will use this. If you need other accounts, set up a batch or shortcut to launch a second instance of Thunderbird using an alternative profile, containing the other accounts. But I think that once this second instance is running, you couldn't stop a mailto: from using it. I think option #2 above is the most likely to work as you want.

Why have you tried to create another profile? What did you want to achieve? Most users who think they need multiple profiles are, IMHO, mistaken. If you do choose to use two profiles, I think you will forever be struggling, finding that whatever you have open, the message you want to refer to or forward is in the other instance.

I don't know what the junk is that appears with your mailto:. That is almost certainly put there by your browser, or the software running and served to your browser. If you can't share it with us here then I doubt we can get any further ahead.

> I don't know what the junk is that appears with your mailto:

It is simply ronks or the other name following the From: field, nothing very complicated. I called it the "account name" in my 7/22 post because, well, that's the name that appears in the "Account Settings | Account Name" field. I suspect the problem may lie with Firefox rather than Thunderbird, or the communication that takes place between them. I believe the issue of accounts leaving residues like this behind after they are "deleted" is not unique to me, from what I have read in other forums. For the moment I have solved the issue crudely, I closed all other apps and simply edited the prefs.js file; I get the results I want through several reboots now. That's enough for me to get work done; I don't need to figure how many profiles fit on the head of a pin or whether accounts have immortal souls. My thanks to everyone who responded.