PHP mail mime and Outlook 2010 Untitled attachments - php

Question

I'm using Pears mail mime to send out emails with attachments in php.
http://pear.php.net/package/Mail_Mime/redirected
It seems Outlook is renaming PDF's to "Untitled..." but it works correctly for gmail, hotmail etc.
Prior to this problem I had another problem where Outlook would not show the file as PDF and attach it as text file unless I specifically tell the mime addAttachment the file type
see the code here:
if (endsWith($file,".pdf")) {
$mime->addAttachment($file,'application/pdf',basename($file));
}
else {
$mime->addAttachment($file);
}
You can see above I've also tried setting the 3rd argument of addAttachment to set the filename, but that hasn't worked either.
Outlook does not rename other file types so it's a catch 22 either set no filetype and have Outlook send as txt file or set the filetype and Outlook renames the files to 'Untitled'

Answer 1

ok found out that Outlook doesn't seem to like long filenames, shortening the filename works.
Pear mime sends a long filename header broken up into parts like this:
Content-Transfer-Encoding: base64
Content-Type: application/pdf;
name*0*=US-ASCII''THIDSO5749_010.901%20-%2013.95505142_GARUDA%20RETARGETI;
name*1*=NG%20CPA%20CAMPAIGN_PT%20GARUDA%20INDONESIA%20%28PERSERO%29%20TBK;
name*2*=._NOV2013.pdf
Content-Disposition: attachment;
filename*0*=US-ASCII''THIDSO5749_010.901%20-%2013.95505142_GARUDA%20RETAR;
filename*1*=GETING%20CPA%20CAMPAIGN_PT%20GARUDA%20INDONESIA%20%28PERSERO;
filename*2*=%29%20TBK._NOV2013.pdf;
size=68426
Outlook can't handle this but it can handle the format:
Content-Type: application/pdf;name="a long filename.....pdf"
Unfortunately it seems Pear mime can't send this format without editing the core code of mime.php
So I'm just sending shorter filenames for now