Please explain how you use "about:profiles" in Thunderbird. You generally need an address bar…

Ah! No! Belay that. It's under Troubleshooting Information.

People who want to run multiple instances of Thunderbird are usually advised to read up about launching Thunderbird with command line switches and maybe to set this up in a batch or whatever scripting or shortcut technology is available to you.

http://kb.mozillazine.org/Run_multiple_copies_of_Thunderbird_at_the_same_time http://kb.mozillazine.org/Profile_Manager#Shortcut_to_a_specific_profile

I have never found good reason to run multiple instances of Thunderbird, since it is quite capable of managing multiple accounts within a single profile whilst also keeping the accounts separate. Multiple profiles seem like an unnecessary headache to me.

Given that you're in Thunderbird, I am not surprised that the button you see launches a new Thunderbird, rather than a "browser" as such. This is possibly generic Firefox code being re-used in Thunderbird.

I can't get it to work. The existing Thunderbird goes pale, indicating loss of focus, but no new instance appears. :-(

Zenos I found the button did nothing. it did not open a browser or another Thunderbird pane. If you did not know how to get "about:profiles" in Thunderbird I suspect that you wer looking in Firefox, The reason for running two instances is that one of the profiles has a bug. Although most links in emails will open, there are some that do not. In a new profile, those links open properly. I have not found a way yet of "refreshing" the original profile to remove the bug whilst keeping all the mail etc.. I wanted two profiles active in the hope that I could select all the mail in a folder , copy and then paste in the Inbox new profile, without keep shutting down one and opening the other.

Getting to "about:profiles": Go to Help thenTrouble shooting information. at the bottom of the first section (Application basics) there is a line headed "Profiles". Along side of that is the link "about:profiles". Clicking that opens a new tab.

Actually, I have found a solution tha opens two (or more) instances. There is an add-in called "ProfileSwitcher".

Ah, yes, occasionally we do see a borked profile that gives errors and a new profile is the most straightforward way to get going again. Whilst it would be nice to be able to compare a working and non-working profile, I think the difference due to the error that breaks it would be drowned out in the sea of legitimate differences.

I'm still not convinced that switching between profiles is especially useful. If you want to transfer messages between profiles then it might be most efficient to copy folders at file system level. Note that by and large you can't usefully copy into an IMAP account folders. However, you can copy them into Local Folders and then transfer them into the account within Thunderbird.

To run two different instances, I created a Thunderbird shortcut icon on desktop. I renamed it to say 'TB Profile Manager' right click on icon and select 'Properties' select 'Shortcut' tab set 'Target' to the following: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" -no-remote -P

This will launch the Profile manager and allow you to select whatever profile you wish. Make sure you have a backup as running more than one instance is not recommended.

some additional info: http://kb.mozillazine.org/Run_multiple_copies_of_Thunderbird_at_the_same_time

It would be "nice to know" which files can be deleted fron a profile that will be rebuilt (as they are at initialisation) when the profile is restarted. Or, is it possible to hace a "redresh" as in Firefox?

Is there a listing any where of files and their function?

Toad Hall Thanks for the suggestion and caution,