Well no particular file, any file can be corrupted in my experience. I've seen corrupted JPG files, PDF files, MS word files, excel files, and even .zip files.
It doesn't matter who send the email, it could happen on any email in my mail box. When I use other application like Thunderbird or Sparrow doesn't cause such issue.
Believe me I know what I'm doing, with the latest Mountain Lion, Latest Adobe Reader I can get from official website and it does not matter which version I'm having. No antivirus program involved, even if there is antivirus program involved, why I don't get trouble in other mail apps?
The problem is, the attachment files in the email was not correctly downloaded. It doesn't matter which program I use to view it. If I save the attached files onto my desktop, situation remain the same. The only possible way I can do is to rebuild the entire mail database. However, the rebuilding process could be hours for I have tons of emails saved on the server, and it does not guarantee will solve the problem. Why bother spending so much time only simply want to get a file? The point is, by using Thunderbird I can get the file instantly, with Mail I can't?
The following is part of the corrupted file's MIME header. I'm not sure if this is enough for I didn't copy the entire header for it contains some sender information. I would probably not sharing those email addresses.
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="=_997f4b2baebbe275a574812f1ca64cdf"
--=_997f4b2baebbe275a574812f1ca64cdf
Content-Type: multipart/ALTERNATIVE;
boundary="=_44f440161c4f3bd3273d9805e6f1454b"
--=_997f4b2baebbe275a574812f1ca64cdf
Content-Disposition: attachment;
filename*0="=?UTF-8?Q?GMOs=20=E0=B9=80=E0=B8=A1=E0=B8=A5=E0=B9=87=E0=B8=94 =E";
filename*1="0=B8=9E=E0=B8=B1=E0=B8=99=E0=B8=98=E0=B9=8C=E0=B8=82=E0=B9=89= E0";
filename*2="=B8=B2=E0=B8=A7=E0=B9=82=E0=B8=9E=E0=B8=94=E0=B8=AB=E0=B8=A7=E 0=";
filename*3="B8=B2=E0=B8=9927072555_0000.pdf?="
Content-Type: APPLICATION/PDF;
name*0="=?UTF-8?Q?GMOs=20=E0=B9=80=E0=B8=A1=E0=B8=A5=E0=B9=87=E0=B8=94=E";
name*1="0=B8=9E=E0=B8=B1=E0=B8=99=E0=B8=98=E0=B9=8C=E0=B8=82=E0=B9=89=E0";
name*2="=B8=B2=E0=B8=A7=E0=B9=82=E0=B8=9E=E0=B8=94=E0=B8=AB=E0=B8=A7=E0=";
name*3="B8=B2=E0=B8=9927072555_0000.pdf?="
Content-Transfer-Encoding: base64