On May 22, 2008, at 2:57 PM, John Levine wrote:
BATV could then rely upon the use of the "-" in Verp to ensure
No such luck. Existing VERP implementations use all sorts of
delimiters, and you can't count on finding a hyphen.
It still seems placing more restrictions on the BATV tag character set
would be a safer choice. In addition, perhaps the tag could be
bracketed by "=" to better ensure uniqueness as well.
=batv1=kiiihhhh=local-part(_at_)dom(_dot_) (iii could be an index maintained
per local-part or the entire domain)
The danger seem to be when services within a domain uses something
like VERP which might become confused with an invalid BATV tag. The
concept of having MUAs apply their own BATV tag requires outbound MTAs
to be robust in recognizing these tags.