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Bulk Email
Bulk email is supposed to be the
most efficient and cost effective way of advertising ever invented. However, in
recent years the task of sending mass quantities of emails (bulk email sending) has become increasingly
difficult.
There are two popular methods of sending bulk
emails: directly and via an SMTP server, each with it's pros and cons. Here we will
discuss each of these bulk email sending methods and the various ways they get blocked.
Direct bulk email sending: 1. The most
effective way of blocking this bulk email sending technique is by now allowing any
email messages through which originate from a dynamic IP address. A dynamic IP address
is what you get when you connect to the internet using a dial-up or DSL connection
or the like. Dymanic IP address ranges are available to everyone and so this bulk
email blocking
technique is possible. I do not know of any way around it. The drawback of such
a technique is that it will block wanted message as well as unwanted, since not
all messages will originate from static IP addresses.
2. The second way of blocking this bulk
email sending method is by checking that the IP address corresponds with the sender
address. This is called a reverse DNS check. It is also a very effective bulk email
blocking method.
3. IP black lists. This bulk email fighting method is very very common. This is used by either setting up bulk email traps (email addresses
which are only meant for intercepting bulk email campaigns) or receiving reports
(complaints) and then putting the IP address of the sender in the bulk email
black list. This
is done very fast, so if one began sending your bulk email in the morning, by lunch time he could
be completely blocked. Since IP addresses are too few and since the RBL's (this
is how they are called) databases are limited in size, usually if no report of bulk emails sent arrives
regarding that same IP address, it will be deleted from the bulk email black list after 24 hours.
Sending bulk email via an SMTP server: The bulk email blocking
techniques employed here are content based. They change all the time and they are
also used to block the bulk email direct sending technique. They include for example: checking
for repeating subject lines, repeating sender addresses, repeating messages, checking
the existance of black listed domains (oh, these exist as well) inside the bulk email message,
checking the existance of any link at all in the message (sometimes), checking if
the message contains a line like "if you would like to be removed from our list..." (as is commonly the case
with bulk email),
checking for certain keywords in the message (usually which have to do with drugs)
etc.
It is not possible to beat all of the above
techniques all the time when sending bulk emails but it is possible to beat most of them most of the time.
A good starting point would be to use a
good bulk email sending program like Email Beast™.
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