On Tue, 6 Jun 2006, Joseph Brennan wrote:
--On Wednesday, June 7, 2006 12:23 PM +1000 Stewart <[EMAIL PROTECTED]>
wrote:
if ($MessageID =~ /<[a-z]+\@(columbia|COLUMBIA)/)
No! For one thing just plain domain.com could be a hostname. But
also, the Message-ID is not required to contain a hostname.
The format of Message-ID (see RFC 2822) boils down to "<", string,
"@", string, ">". Therefore a Message-ID <[EMAIL PROTECTED]> is
properly formed as per the standard.
However the purpose of Message-ID is to be a unique identifier, and
by ancient practice this is done by putting the sender's hostname in
the second string and something usually involving a timestamp in the
A practice RECOMMENDED by RFC2822 section 3.6.4. Even further "The message
identifier (msg-id) itself MUST be a =>globally unique identifier<= for a
message." To put another domain's name into a message ID is certain
failproof for _not_ generating a globally unique ID.
first string. As a result we don't expect to see "columbia.edu" as
the second string, nor all small letters in the first string, so we
can reject on that.[*]
You've blocking any host of spaceship enthusiasts as well, unless you
anchor 'columbia' to the end of the string somehow.
[* In fact all small letters in the first string is never generated
by any legit mail client or server that I know of, so you could reject
on just simply:
if ($MessageID =~ /<[a-z]+\@>/)
But there is at least one server, mailcity.com, that generates all
Found some legal mails from mshome.net and MSK.SU that use [:alpha:]+ on
the lefthand side. However, you've put the '>' in the pattern in error,
right?
capital letters in its first string. I don't know how this gets them
unique Message-IDs.]
Once you have an unique ID, you can represent it with any (legal)
characters you like, can't you? E.g. radix 26 with the "digits" a through
z. :)
Bye,
--
Steffen Kaiser
_______________________________________________
NOTE: If there is a disclaimer or other legal boilerplate in the above
message, it is NULL AND VOID. You may ignore it.
Visit http://www.mimedefang.org and http://www.roaringpenguin.com
MIMEDefang mailing list [email protected]
http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
