[Enigmail] Encrypting a reply with enigmail: Send Message Error

[Dominik Herting]

My setup

Mac OS X 10.4.10, TB 2.0.0.6, Enigmail 0.95.3 with GPG 1.4.3.

Whenever I reply to an encrypted&signed message, Thunderbird
automatically selects to encrypt my reply as well (a good thing, of
course). I go ahead and type my message and finally click on "Send".
Normally I would expect to see the encrypted text of the message for a
second while Thunderbird connects to the SMTP server and transmit the data.

With encrypted replies I get the folowing error, though: "Send Message
Error - Sending of Message failed. Please verify that your Mail &
Newsgroup account settings are correct and try again." In the message
window I see the encrypted version of the text.

What I have to do as a workaround: Copy the encrypted text into
clipboard, close the message window, reply to the message again,
DEselect the encrypt option in the menu, paste the encrypted text into
the message window, send the message. Unfortunately, this procedure
leaves out the appropriate message headers which causes spam filters to
treat the message as likely spam (no legible contents, only gibberish in
a plain-text message is suspicious).

I have already asked this question here:
http://forums.mozillazine.org/viewtopic.php?p=3088464

... but did not receive help yet. It seems that I am not the only one
experiencing this problem, though.

Thanks for your help!

Dominik