Just for your information (you don't have to reply if that already has been
discussed):
The mail server of ifw-dresden.de does not accept '/' in the envelope sender
(see sample below). But SRS uses base64 to encode the hash and therefore
there is a chance of 6.25% that there will be a slash in the envelope
sender.
I have found out so far that the only characters in email addresses accepted
by all mail servers are: letters, digits, '_', '+', '-', '*', '='.
Futher, many mail servers (e.g. yahoo.com) convert the envelope sender to
lower case when bouncing a mail.
An alternative encoding would be base41 (just invented by me) to encode 2
bytes into 3 characters using following characters:
abcdefghijklmnopqrstuvwxyz0123456789_+-*=
HELO mail.pamho.net
< 250 mail.ifw-dresden.de Hello mail.pamho.net [81.221.18.146], pleased ...
MAIL FROM:<localpart=hs+t/p1mm(_at_)pamho(_dot_)net>
< 501 5.1.7 Malformed envelope from address: invalid punctuation characters
Roger