Your Server is getting blocked because of
incorrectly configured reverse DNS or S25R rules.
After setting up your mail server it is important to insure that your DNS
entries are properly configured in order to not have your mail rejected by many
of the email filtering service providers or ISP's.
Your IT support company should set this up for you, however many don't pay
attention to the details. The issues involve Exchange Servers in which the
DNS server's PTR records are not correctly configured.
Many times the IT company will setup a forward record which is something like
mail.YourDomainName.com pointing to the IP number of your server 220.127.116.11.
The problem lies in the reverse of the IP number. The ISP providing you
DSL/T1 etc usually has something configured for reverse DNS that
looks like bb219-74-49-238.YourISP.com or adsl-123-132-5.mia.bellsouth.net.
As you can see these reverse DNS entries have no association with
mail.YourDomainName.com and many Internet Service Providers and
email providers, such as MSN, AOL and Hotmail, block spam by using reverse DNS
lookups on incoming email server.
The proper setting for the
example we have of mail.YourDomainName.com would have a reverse DNS entry of
18.104.22.168 pointing to mail.YourDomainName.com. Your mail server will now
comply with the mail server standards and you won't get blocked becuase of
anti-spam policies such as
If you configure your server properly you will prevent yourself from getting
rejected email messages utilizing these policies.
if you have problems with your mail server Innovative Internet Solutions can fix
You can contact us
Further information about the Official
Internet Protocol Standards can be found
here as well as