• We will not be able to receive emails from internet and a genuine senders will get the following NDR;
• #550 5.7.1 :126.96.36.199:Client host 188.8.131.52 UnknownDNSName; Mail from IP banned. To request removal from this list please forward this message to firstname.lastname@example.org
• You may get the following Event id as well in the Application log;
Log Name: Application
Source: Microsoft Forefront Protection
Date: 9/7/2010 3:18:07 PM
Event ID: 2098
Task Category: General
The DNS Block list lookup domain blocklist.messaging.microsoft.com could not be contacted. This will prevent DNS Block list lookups. Please verify your network connectivity.
FSE connection filtering DNSBL checking.
• Go for Rollup 1 or disable FSE connection filtering;
• Description of Hotfix Rollup 1 for Microsoft Forefront Protection for Exchange