Quondam said:
I receive this message when using OL. "Server response '250
Pipelining' Account ("my account" SMTP Server smtp.theirserver.com
Error Number 0x800ccc7d)"
The 250 level message is a message indicating successful reception by a mail
server of an SMTP command. "250 Pipelining" from the mail server is a
message sent in response to a EHLO command telling the message client
(Outlook, in this case) that the server will continue to accept SMTP
commands from the client until the DATA command (where the main part of the
message is transmitted) is received. Then the server returns in one
transmission all accumulated 250-level messages generated by the SMTP
envelope exchange. Ordinarily, a client and server have a conversation that
does approximately like this:
<Client tried to connect to the server and waits for it to answer>
Server: Hi. I'm you're server. My name is TheirServer.com
Client: Hello, I'm QuondomDomain.org (this is the HELO command)
Server: Hello, QuondomDomain.com
Client: I'm sending mail from Quondam
Server: Address Quondom looks OK.
Client: I want the mail delivered to User1
Server: I know who User1 is
Client: I want the mail delivered to User2
Server: I know who User2 is
Client: I want the mail delivered to User3
Server: I'm sorry, I don't know anyone named User3
Client: That's all the addresses. Here's the message (this is the DATA
command)
Server: OK, send the message
Client: Here it is................................
Client: That's it
Server: I got it. Thanks
Client: That's all for now. Bye
Server: Bye
With Pipelining, the give-and-take between client and server is streamlined.
In essence, the conversation is supposed to go like this:
<Client tried to connect to the server and waits for it to answer>
Server: Hi. I'm you're server. My name is TheirServer.com
Client: Hello, I'm QuondomDomain.org and I use extended mail (this is the
EHLO command)
Server: Extended mail, eh? Let's use Pipelining (this is the 250 PIPELINING
message)
Client: I'm sending mail from Quondam
Client: I want the mail delivered to User1
Client: I want the mail delivered to User2
Client: I want the mail delivered to User3
Client: That's all the addresses. Here's the message (this is the DATA
command)
Server: Address Quondam looks OK
Server: I know who User1 is
Server: I know who User2 is
Server: I'm sorry, I don't know anyone named User3
Server: OK, send the message
Client: Here it is................................
Client: That's it
Server: I got it. Thanks
Client: That's all for now. Bye
Server: Bye
The pipelining feature was first introduced into mail clients and servers in
September of 2000 and it took a while to be added. Apparently your server
knows about it, but your Outlook version doesn't and so can't recognize the
250 response. I doubt if there's anything you can do other than upgrading
Outlook to a newer version.
