This has been implemented in CVS already and will be released with IMP 4.1.

Some messages contain information at the top about the MIME parts, see 
the sample at the end for an example. This causes message previews to 
display this ugly text instead of the start of the actual message.



A partial fix/hack is to remove the MIME info from the preview with a 
regex. In horde/imp/lib/Mailbox.php, after line

294: $ptext = trim(strip_tags(@imap_fetchbody($imp['stream'], 
$header->msgno, 1)));

insert the line

$ptext = preg_replace('/^.*Content\-Transfer\-Encoding\:.*?\n/s', '', 
$ptext, 1);



This only works if the first message part, that imap_fetchbody fetches 
is the plain text part. If it is an attachment or something then we 
can never get the text from it. To handle all situations, we'd have to 
add in some code to make sure we fetch the plain-text part of the 
message (if there is one of course) to use for the preview.



** BEGIN MESSAGE SAMPLE **

This is a multi-part message in MIME format.

--------------050807000301030204090007

Content-Type: multipart/alternative;

  boundary="------------010801040006060501020508"





--------------010801040006060501020508

Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Content-Transfer-Encoding: 7bit

** END MESSAGE SAMPLE **