🚀 go-pugleaf

Why use the From: or Date: fields at all?  The From: field is a popular
candidate for editing by automatic agents; I'm not convinced that Mr. Palme's
algorithm will remove all traces of that editing.  The Date:-field
algorithm was underspecified (year in century, as SMTP would have?  What
is the origin for months?  Any use of time zone information?).

For that matter, I'm not sure that all agents would agree on the concept
of ``printing character'' in the body of the message.

Why not use an algorithm based solely on the body of the message?  It can
ignore characters outside the range [33,126] (decimal, inclusive); obviously
it would only count characters in that range when incrementing the checksum
counter.

It may be less expensive to use something other than multiplication as a basis
for the checksum on many small machines.  Are there suitable algorithms based
on bit rotations or shifts?

And perhaps the whole discussion should be moved into an RFC.