Comment 79 for bug 357864

(In reply to comment #78)
> So what is the best solution so far for this problem? Which extension works
> best with Thunderbird 1.0.2 (if any) or which patch (if any)? Thank you.

I posted back in March about this, but since then have been using Thunderbird
which pretty much does what I originally wanted.

I know I'm not telling anyone here anything they don't know, but I just wanted
to close up my post by saying I have found a solution which suits me.

In Thunderbird, although the From header in the compose window is not editable,
you can set up as many identities as you want from the Account Settings menu.
These identities are then selectable within the compose window using a list.
Also, if someone sends you an email to one of your identities, Thunderbird
automatically uses this address when you click reply so you don't need to
remember to change it yourself.

As I said, not exactly what I wanted, but it does the job very well. You only
need to set up the identity once (very quick to do) and from then on it is
available for you to use. Excellent!