Just got sent a pointer to:
<http://www.email-standards.org/>
which seeks to rate MUAs and webmail sites for standards compliance.
In fairness, the only "compliance" they are testing is HTML-message
compliance.
Nothing that actually relates to SMTP specifications at all, sadly. :-(
--
Derek J. Balling
Manager of Systems Administration
Vassar College
124 Raymond Ave
Box 0406 - Computer Center 229
Poughkeepsie, NY 12604
W: (845) 437-7231
C: (845) 249-9731
smime.p7s
Description: S/MIME cryptographic signature