Understanding ISP-Level E-Mail Filtering
From last few years spamming is the key factor which is
exasperating whole of the virtual world. To fight back spamming
the emails get filtered through the ISPs. But I must add with
your information that all of the email messages getting through
the filters have great influx over them and also the human
resources. They are also the major sources for the complaints
from customers and satisfaction.
All of the email messages are going through the ISPs filter and
where it matches the spammer appearance they are listed and
moved to the spam.
But it is merely a difficult thing to check what are the
criteria used by different ISPs for the spamming. Some of the
components which may be common with the ISPs for spam are to be
mentioned for your assistance which will help you avoid getting
in to the list.
Some of the main features for the email spamming used by nearly
all ISPs are:
- Sender reputation.
- Sender authenticity.
- Volume of messages sent.
- Volume/percentage of invalid addresses (hard Bounces)
- Message Content.
- Spam Complaints.
The spam filter uses multiple levels. A message passes through
these different levels of the pyramid.
• Blacklist: blacklist is the one in which all of the spammers
are listed. Your email message has to pass through this level
for verification if you are listed with the list or not. If you
are listed with this blacklist your message is deleted right
away if not then your message will be directed to the next
• SMTP Transaction: the way your email message appears can lead
your message to the next level. The message behavior is what
which lets the ISP define whether your message is to be
delivered or deleted.
• Mail Streams: the ISP looks at your email message stream
behavior as a whole. If your message is directed to hundred of
email recipients, where the email addresses are listed in the
single to line then it is more likely that it is read to be the
spam and directed to the spam or deleted anyway.
• Top level filters: once a connection is set up between servers
and the message content is exchanged the top-level filters step
in. it is the scanner for the message content. This is the level
where red flags are picked. Red flags include sexually explicit
materials, offers for brand name prescription drugs, bluntly
attempts to complicate words and other spammer tricks.
• User-level filter: this is the filtering at the personal
level. When an email message passes through all of the levels
and get to you and you don't feel like using or you don't need
such kind of email messages then you filter them out on your
own. You click the delete button or the spam button or ask the
message to get in to the junk box. The filter used for the
personal use is known as "learning filter". This let the ISP
know what is the pattern you use for the receiving an email
The above mentioned are the levels through which the email
message passes through.