I am not sure if this is a bug in mail.app, or a configuration I just can't find. It might also be a strange sideffect of GPGmail.
Mail.app correctly displays all e-mails on my IMAP server, except for the e-mails in my "Sent Messages" folder. In the sent messages folder it messes up åäö, in typical quoted-printable with wrong char-set fashion. They become ‰ˆ.
When looking at the source of the e-mails it seems like the header generated by mail.app is correct:
Message-Id: <>
From:
To:
In-Reply-To: <>
Content-Type: multipart/signed; protocol="application/pgp-signature";
micalg=pgp-sha1; boundary="Apple-Mail-4--741321197"
X-Smtp-Server: smtp.example.com
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0 (Apple Message framework v936)
Subject: Example subject
Date: Fri, 26 Mar 2010 10:14:14 +0100
References: <>
X-Pgp-Agent: GPGMail 1.2.0 (v56)
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--Apple-Mail-4--741321197
Content-Type: text/plain; charset=ISO-8859-1; format=flowed; delsp=yes
Content-Transfer-Encoding: quoted-printable
<Text here with =E5=E4=F6>
--Apple-Mail-4--741321197
content-type: application/pgp-signature; x-mac-type=70674453;
name=PGP.sig
content-description: This is a digitally signed message part
content-disposition: inline; filename=PGP.sig
content-transfer-encoding: 7bit
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.12 (Darwin)
iEYEARECAAYFAkus62kACgkQlIRLofxhDjYnnwCcDmCXuMGsKlh3a418s12coJgn
36sAoKMdkP3+g/OMK+Ps7AbjQq4Nbqzv
=XMko
-----END PGP SIGNATURE-----
--Apple-Mail-4--741321197--
How can I get mail.app to use the correct charset?
Some more test results:
- Thunderbird has no problem displaying the messages.
- When I send a message to myself it displays correctly in the Inbox, but incorrectly in the Sent folder. But: moving the message from Sent to Inbox does not change the erroneous formatting.
- Turning off signatures makes the messages display correctly in the Sent folder as well. The only difference I can see (beyond headers added in transfer), is the
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)line added before the first mime block.

smtp.gmail.com). Hence, it could also be a combination of Mail and the IMAP server. (Some Thunderbird IMAP madness at superuser.com/questions/42009/…, just as an aside.) Maybe manually moving messages from Sent into the Inbox can give you more insight if Mail handles the two mailboxes differently, or if the server converts it? – Arjan Mar 29 '10 at 9:36