Erin contacted The Guru with the below question. I tried doing a Google Search and checking the mozillaZine forums without much luck so may be someone else here can give us some advice:
Since we upgraded to Thunderbird version 2.0.0.19 it seems that not all HTML attachments are treated the same (when sent). Those with ^M are sent as “quoted-printable” text (results in a problem) and the same file without ^M is send encoded base64 (producing desired results). Is there a way to force Thunderbird to treat them all the same? Thanks.
Have either of you filed a bug report? If it is reproducible, that would bring it to the developer’s attention, and most likely get you a solution or workaround.