Hi Mike & friends.
Speaking as somebody whose e-mail service always "reformats" my outgoing mail, I agree with your concerns. Mr. Aust has also expressed concerns on this subject and his proposal was to use Squeak's compression feature to compress your files before attaching them to e-mails. In general, I agree with his suggestion because it makes the e-mails smaller and they are free of e-mail artifacts (and because I get leverage Squeak instead of some other product). :-)
Cheers,
---==> Chris