Mail header question

What's the difference in the headers between the To and X-Originally-To and

pmj...

The difference is the "X-Originally-" bit!
:-)

what does it mean when they are two different addies ? Genuine mail BTW just

pmj...

It could mean anything at all...

curious 'cos it didn't go into the folder it should have.

pmj...

Well, that would depend on what Rules & filters you have Set up -
& what they are looking for & the Actions that are set for them.

But the main thing to remember about Headers such as you have mentioned
is that *by definition*, any Header (in an RFC(2)822 Message) that is
an "X-" Header, is *UN*Defined!!!

The whole point of "X-" Headers is that they are *specifically* defined
in the RFCs as being UnDefined - in other words they can be used for
whatever purpose anybody wants - other Headers (that don't begin with
"X-") have specific purposes, but *any* Header that begins with "X-" is
explicitly designated to be UnDefined.

The idea is so that various Mail Systems can use them for their own
purposes & be sure that any other (correctly Set up) Mail System won't
be thinking of them as being PreDefined.

In other words, if you want to know what a particular Header is used
for, you can look it up in the RFCs & if a firm wants to use a Header
for their own purposes, they should use an "X-" Header & you would have
to check out the Documentation & Info for whatever System put that
particular "X-" header into the Mail.

For more Info about "X-" Headers, (& Headers in general) see the RFCs,
such as...

RFC0822 - STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES
(Obsoleted by RFC2822) (Updated by RFC1123, RFC1138, RFC1148,
RFC1327, RFC2156)
4. MESSAGE SPECIFICATION
4.5. RECEIVER FIELDS
4.7. OTHER FIELDS

4.7.4. EXTENSION-FIELD
A limited number of common fields have been defined in this document.
As network mail requirements dictate, additional fields may be
standardized. To provide user-defined fields with a measure of safety,
in name selection, such extension-fields will never have names that
begin with the string "X-".
Names of Extension-fields are registered with the Network Information
Center, SRI International, Menlo Park, California.

4.7.5. USER-DEFINED-FIELD
Individual users of network mail are free to define and use additional
header fields. Such fields must have names which are not already used
in the current specification or in any definitions of extension-fields,
and the overall syntax of these user-defined-fields must conform to
this specification's rules for delimiting and folding fields. Due to
the extension-field publishing process, the name of a user-defined-field
may be pre-empted
Note: The prefatory string "X-" will never be used in the names of
Extension-fields. This provides user-defined fields with a protected
set of names.

Note that last bit, which is what "X-Originally-To: " Header Field
you mentioned.

Also, have a look at Articles such as...

Common Internet Message Header Fields

& for Info about the particular Usage of the "X-Originally-To: " Header,
in any Message you have Received, you would have to refer to the
Documentation for the Mail System that added it.

It's *usually* used (inserted by Mailing Systems) to indicate that
the original "To: " Header has been changed (for whatever reason the
Mailing System has for doing that, which could be lots of reasons,
such as ReDirection or Mailing List purposes etc,) & so as to enable
the original Contents of the "To: " header Filed to still be available,
so you can Search for it & act on it accordingly.

But things like OutLook Express don't cater for Searching (or Filtering
on) "X-" Headers, they only Read the "To: " From: " "Date: " &
"Subject: " Headers.

If you want to do any Filtering on other Headers, then you would need
a different Mail Client (or use the Facilities available on your Mail
Server.