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451 All MX servers are unavailable for domain yahoo.com

i am trying to send e-mail from my corporate account to yahoo.com

the email goes out from my exchange 2010 to mxlogic servers and then to outside world

i am only having problem with yahoo domain

can u suggest any solution
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1 Solution
can you post the NDR??  

Are you sure emails are going to the mxlogic servers vs directly out from yours (ie.  you have the mxlogic server as your smarthost usually <domain>.outbound10.mxlogic.net)??  Also you put your mail server IP in your mxlogic portal???
B HCommented:
we had the same problem with yahoo today... yahoo did some kind of policy change where if any yahoo member clicked 'spam' on any email address sent from your server, the sending ip is banned.  not sure how long their new policy will last, but i went here and requested to be unblocked (see below)

to find the link, i had to manually telnet to one of their mx records (a.mx.mail.yahoo.com) and it immediately said we were temp-banned:
421 4.7.0 [TS02] Messages from my.wan.ip.addy temporarily deferred -; see http://postmaster.yahoo.com/errors/421-ts02.html

i went to that link, requested to be unbanned, and 4 hours later i was

i did go set up their new "complaint feedback loop" (http://feedbackloop.yahoo.net/) which is a serious pain in the ass, but ensures we won't be banned again...

the basic steps were:
1. set up a CFL account with them (free)
2. find and install a DomainKeys signature writing smtp sink ($300 after 15-day trial)
3. publish the public key (rsa) as a text record in our dns

I'm having the same issue and would like to see if you can test a theory:

Do you have any rules configured in your firewall to only allow SMTP traffic directly from MX Logic?  Try configuring your firewall to allow SMTP traffic (temporarily) from anyone.  Then restart the SMTP service on your email server.

For some reason, this seems to work for me.  The email is not sent immediately - it still takes about 10 minutes to be delivered to Yahoo.

I don't think this has to do with SPF records, or using (not using) DomainKeys.  If I configure the email server to bypass MX Logic as a smarthost, the email get's delivered to Yahoo immediately (5 seconds in my testing).
B HCommented:
In your case, mxlogic is temp banned from yahoo, not you
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