u n s u b s c r i b e link in message body

Hello!

(I hope Majordomo at greatcircle doesn't discard this message as 
administrivia. It contains lots of administrivia words)

I have a very interesting problem involving Majordomo and Mozilla 
Thunderbird.

I've set up a message footer for one of our lists. The last line of the 
footer is:

To unsubscribe, click here: 
mailto:[email protected]?body=unsubscribe%20ourlist

If a message is received via the list and is viewed with Mozilla 
Thunderbird, the word "subscribe" is displayed instead of "unsubscribe". 
This is, of course, counter-productive :-)

If I view the raw source of the message, it contains "unsubscribe" as it 
should.

The problem appears no matter if I look the message with Thunderbird 
1.0RC (Windows) at work or Thunderbird 1.0.2 (FreeBSD) at home. In both 
cases I'm looking at the same message in the same IMAP mailbox.
If I look this message via IMP webmail interface, it looks OK.

Other members of the mailing list who are using Lotus Notes 6.5 are 
seeing "unsubscribe". Haven't had a chance to check other mailers.

If I send identical text to myself directly (so it doesn't go through 
Majordomo), the result is displayed correctly in Thunderbird.

It may be worth mentioning that the message_footer contains some 
non-ascii characters (it's in Estonian), but these characters are 
displayed correctly.

What on earth is going on here?

Software versions:
Majordomo 1.94.5
Perl 5.6.1
Postfix 2.1.1
FreeBSD 5.3

-- 
Toomas Aas