Hi,

 I have installed Ex2013 on a separate box.  Over the weekend I have switched the 2010 CAS role to my new CAS server.  I update the external url's on the virtual directories on the new CAS server swapped out the ip's of my 2010 exchange putting it on the new one (as I don't have to make any changes to my public dns records) and set a new ip for my 2010 cas box with mailboxes.  Last, I updated the internet connector to include my new CAS server as a source server.  Basiscally, everything works fine except the now we can't send any external emails.  We got an undeliverable message saying that "client host x.x.x.x blocked using block list 1, mail from IP banned............

HI

just check if your connecting IP is blacklisted with any of the providers . If its blacklisted contact the appropriate providers to whitelist them. Usually it takes not more than 24 hours to whitelist them.

YOu can checkby typing your Connecting public IP on the below link

http://mxtoolbox.com/blacklists.aspx

Please mark as helpful if you find my contribution useful or as an answer if it does answer your

question.That will encourage me - and others - to take time out to help you.
Regards,
Sathish

WE are not black listed.  We can send /receive internal mails, send external mails except to office 365 users and maybe to one or two other domains (I.E. Shell and Brandman University).  Other than that everything is working fine.  We always get a NDR like this on blocked messages:

CO9EHSMHS015.bigfish.com rejected your message to the following e-mail addresses:

CO9EHSMHS015.bigfish.com gave this error:
Service unavailable; Client host [4.30.210.34] blocked using Blocklist 1, mail from IP banned; To request removal from this list please forward this message to delist@messaging.microsoft.com and include your ip address 4.30.210.34. 

We had requested several times to be delisted and yet to hear any news from Microsoft.  It's really killing us.

Joe

Hi Joe,

Based on your NDR, it indicates that your IP address 4.30.210.34 is blocked in the BlockList . If you want to remove your address from the list, you need send a message to delist@messaging.microsoft.com with your IP address.

Additionally, if you want to send external message from Exchange 2013 server, it is recommended to change the primary host names, such as mail.contoso.com, autodiscover.contoso.com, and owa.contoso.com (if used) to point to the external, publically-accessible, IP address of the Exchange 2013 Client Access server with your public DNS provider instead of an external IP of your original Exchange 2010.

In other words, you might need to make changes to your firewall to support the new Exchange 2013 server. You might need to add new firewall rules, add an external IP address for your Exchange 2013 server, or make other configuration changes. For more information about configuring DNS records, we can refer to:

http://technet.microsoft.com/en-us/library/dn307232(v=exchg.150).aspx

Checklist: Upgrade from Exchange 2010

http://technet.microsoft.com/en-us/library/ee332309(v=exchg.150).aspx

Thanks,

Hi Winnie,

 Initially we did get blocked but now we have since been released.  The baffling part of this issue is, we can send to some external recipients and some of them gets blocked. We took out the IP'S from the EX 2010 box and assigned it too the new 2013 CAS and used a new IP for the 2010 box.  Hence, the forwarding on the firewall should not be an issue.  We did flush and reregister dns on the boxes making sure it's updated also.