Can't send mail to yahoo! An SMTP Protocol error occurred

[Thiyagu_2]

Hi everybody!

My users can't send mail to yahoo. But they can send to any other domain except yahoo without any problem.

When I see the Queue in Exchange System Manager,
I found that they are queued. The status of the queued mails says that "An SMTP protocol error occurred"

I wonder how other mails except yahoo goes without any problem.

What could be the problem.

Help me soon.Thanks in advance.

[Ron Kinner]

We had a problem last month with our DNS server which caused a similar problem.

open a CMD window and check the browser lookup by typing:

nslookup yahoo.com

you should get:

"Server: YourDNS.com
Address: A.B.C.D


Name: yahoo.com
Addresses: 66.94.234.13, 216.109.112.135"

Now check the lookup for mail connections:

nslookup
set type=mx
yahoo.com

This is what you should get:

Server: YourDNS.com
Address: A.B.C.D

yahoo.com MX preference = 1, mail exchanger = mx2.mail.yahoo.com
yahoo.com MX preference = 1, mail exchanger = mx3.mail.yahoo.com
yahoo.com MX preference = 5, mail exchanger = mx4.mail.yahoo.com
yahoo.com MX preference = 1, mail exchanger = mx1.mail.yahoo.com
yahoo.com nameserver = ns1.yahoo.com
yahoo.com nameserver = ns2.yahoo.com
yahoo.com nameserver = ns3.yahoo.com
yahoo.com nameserver = ns4.yahoo.com
yahoo.com nameserver = ns5.yahoo.com
mx2.mail.yahoo.com internet address = 64.156.215.8
mx2.mail.yahoo.com internet address = 67.28.114.35
mx2.mail.yahoo.com internet address = 67.28.114.36
mx3.mail.yahoo.com internet address = 64.156.215.18
mx3.mail.yahoo.com internet address = 64.156.215.5
mx3.mail.yahoo.com internet address = 64.156.215.6
mx3.mail.yahoo.com internet address = 64.156.215.7
mx4.mail.yahoo.com internet address = 206.190.36.244
mx4.mail.yahoo.com internet address = 216.136.129.5
mx4.mail.yahoo.com internet address = 66.218.86.197
mx4.mail.yahoo.com internet address = 66.218.86.199
mx4.mail.yahoo.com internet address = 206.190.36.245
mx1.mail.yahoo.com internet address = 64.157.4.78
mx1.mail.yahoo.com internet address = 67.28.113.10
mx1.mail.yahoo.com internet address = 67.28.113.11
ns1.yahoo.com internet address = 66.218.71.63
ns2.yahoo.com internet address = 66.163.169.170
ns3.yahoo.com internet address = 217.12.4.104
ns4.yahoo.com internet address = 63.250.206.138"

>exit

Now pick one of the mx addresses and:

telnet 64.156.215.8 25

You should get:

220 YSmtp mta290.mail.scd.yahoo.com ESMTP service ready

Ron

[Thiyagu_2]

Ya! As you said I can do that, but still my mails are in the Queue only.

Is there any solutions like this.

Thanks in advance

[Rune J. Winje]

If all DNS etc looks correct - it may also be that your Exchange server for some reason has appeared on a "black list":

http://support.microsoft.com/?id=300580
"This issue may occur if the computer that is running Exchange 2000 or Exchange 2003 is listed as a messaging server that sends unsolicited commercial e-mail (UCE, also known as spam). This behavior may occur if the computer that is running Exchange 2000 or Exchange 2003 is an open mail relay."


Cheers,
Rune