Sathish Veerapandian

Issue: Unable to send mails from IMAP/SMTP clients.

Recently i came across an issue with unable to send emails externally to our domain from IMAP/SMTP clients and found an solution for the same

Hope this would be helpful for others if similar issue occurs

Issue: Unable to send mails from IMAP/SMTP clients.
Error: 5.7.1 The client does not have permission to send as this sender.
Resolution: The sender specified in the MAIL FROM field of the SMTP protocol conversation is an address in an authoritative domain.
However, the session doesn’t have the ms-Exch-SMTP-Accept-Authoritative-Domain-Sender permission. This might occur if a message was submitted from the Internet to an Edge Transport server from a sender address for which the Exchange organization is authoritative
 Shell Command#
Get-ReceiveConnector “Default SERVER01” | Add-ADPermission -User “NT AUTHORITY\ANONYMOUS LOGON” -ExtendedRights “ms-Exch-SMTP-Accept-Authoritative-Domain”
Get-ReceiveConnector “Default SERVER01” | Add-ADPermission -User “NT AUTHORITY\AUTHENTICATED USERS” -ExtendedRights “ms-Exch-SMTP-Accept-Authoritative-Domain”

A related article which talks about the permission and error:

Exchange 2007 Transport Permissions Model
http://technet.microsoft.com/en-us/library/aa997170(EXCHG.80).aspx

BUG in Forefront security for exchange 2010

Symptoms:

• We will not be able to receive emails from internet and a genuine senders will get the following NDR;
• #550 5.7.1 :67.215.65.132:Client host 131.107.10.4 UnknownDNSName; Mail from IP banned. To request removal from this list please forward this message to delist.forefront@messaging.microsoft.com
• 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
Level: Error
Keywords: Classic
User: N/A
Computer: EMAIL.hsh1.com
Description:
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.

Cause:

FSE  connection filtering  DNSBL checking.