"yahoo.com envelope sender" blocks outgoing messages - help!

[Joseph Leahy]

First of all, I am able to send e-mail messages using Pine,
so there is no server problem. Also, I have not changed
any settings on Outlook. Here is what is happening as of
today:

- my outgoing messages are rejected by the server

- I get the following error message "The message could not
be sent because one of the recipients was rejected by the
server. Server Response '451 4.3.0 Reverse DNA information
required for yahoo.com envelope sender.'


I do not have any of my settings (that I know of) in
Outlook set to anything relating to yahoo. I do have a
separate yahoo e-mail that I use on occasion through
Internet Explorer, but I don't see the connection, if there
is one.

Please help!

 

[Lanwench [MVP - Exchange]]

Hi - I think you mean "reverse DNS". Whose SMTP server are you using for
outbound mail? The problem lies there, in the public DNS for that mail
server's domain/MX record.

 

[Joseph Leahy]

Yes, oops, I meant DNS. Anyway, this is a university e-
mail server, and I don't think anyone else is having any
problems. Also, my e-mails are able to go through using
Telnet/Pine, so doesn't that mean the problem is with my
Outlook software?

Joe

 

[Lanwench [MVP - Exchange]]

Not really - the message is because of the sending server. Have you talked
to the admins? Do you know for sure you're connecting to the same SMTP
server when you run telnet/pine?

 

[*Vanguard*]

"Joseph Leahy" said in news:[email protected]:

Yes, oops, I meant DNS. Anyway, this is a university e-
mail server, and I don't think anyone else is having any
problems. Also, my e-mails are able to go through using
Telnet/Pine, so doesn't that mean the problem is with my
Outlook software?

Joe

Sounds like the SMTP server to which you are sending uses the IP address
for your connection (always known by whomever you connect to) to perform
a reverse DNS and expects an MX record showing the IP name of the
sending mail server. They probably want to make sure it is a mail
server rather than an off-domain e-mail client (which doesn't have the
authority to use that receiving mail server).