Are You Getting
Bounced E-Mail To Specific Recipiants?
Some
individuals who have their own mail server operating on a
dynamic IP address sometimes encounter a specific situation.
They find that sometimes their email messages are delivered
to some recipients but refused by the email server of other
recipients. One of the reasons that this occurs is that some
ISP's such as AOL, Earthlinlk, and others, try to protect
their subscribers from receiving unsolicited SPAM. One way
to accomplish this is to verify that the sender is legitimate
by performing a "reverse lookup." Here's how that
works.
When you send an email
message and your mail server completes the connection with
the receiving server it tells the receiving server your current
IP address. This is part of the SMTP protocol (Simple Mail
Transfer Protocol). Your IP address that your server reported
"belongs" to your ISP and it was temporarily assigned
to you by your ISP. The receiving server performs a "reverse
DNS lookup" on your IP address to determine the domain
name associated with that address. (Commonly a DNS lookup
starts with the domain name and then finds the associated
IP address. The "reverse DNS lookup" starts with
the IP address and finds the domain name.) It finds that the
domain name associated with that IP address is the domain
name of your ISP.
Next your server sends
a "HELO" message to the receiving server and that
message contains your domain name. The receiving server compares
the domain name it discovered through performing the "reverse
lookup" with the domain name your server sent. When these
two domain names are not the same then the receiving server
assumes that the email message is SPAM and rejects it. Not
all receiving servers perform the "reverse lookup"
so your email may be rejected in some cases but not all cases.
To solve
this problem you should send your email out through your ISP's
server, not yours. To accomplish that you need to know the
IP address of your ISP's server and you can find that by contacting
your ISP. Some of our customers have told us that their ISP
wasn't immediately forthcoming with that information but they
were able to get the IP address by explaining that they needed
it to configure Outlook for use with the free email account
that the ISP offers and to accomplish that they need the ISP
mail server's IP address. In many cases sending mail through
your ISP will solve the problem sending email from a dynamic
IP address.
For more information or to post questions or comments about
the use of our products please visit our Online Support
Forum.