At 3:30 PM -0500 12/1/00, Scott McDermott wrote:
> Brian Curtis on Fri 1/12 15:21 -0500:
>> qpopper[20154]: [username] at [isp.net] (1.2.3.4): -ERR Unknown
>> command: "xsender". [pop_get_command.c:122]
>
> My guess is that this is just server-side support for parsing X-Sender:
> headers and passing them back to the client. They're not necessary but
> might allow some cases to optimize. They can be safely ignored...we do
> here without problems.
Netscape clients send the "xsender" command, which I believe is a
proprietary extension supported by the Netscape server which returns
to the client the authenticated identity of the message's sender. It
has nothing to do with the "X-Sender" header. As I understand it, if
the Netscape server receives a message in an authenticated SMTP
transaction, it passes the authenticated sender id along to the
client on request via its 'xsender" command.
