Email Hosting Services
Email AntiVirus Protection
SDS's email gateway is updated several times a day with new virus detection signatures.
If an email is detected as containing a virus several things will happen.
- The email recepient (you) will receive a notification of the infected email.
NOTE: The notification is from MDaemon (This is the product name of our email gateway)
- The email administrator (SDS assigned technician) will receive a notification of
the infected email.
NOTE: This allows us to identify potential problems, such as a user with an infected
workstation.
- The infected email will be cleaned.
NOTE: Typically the virus is contained in an attachment. In which case, the attachment
will be removed.
- A notice is added to the cleaned email that had originally contained a virus and
has since been cleaned.
- The now virus-free email is delivered to the recipient.
NOTE: This is just in cases the email is actually valid, but was sent from someone
with an infected workstation. Although most virus infected emails contain no valid
information and was sent for the sole purpose of infecting your workstation.
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Email AntiSPAM Protection
YOU CANNOT ELIMINATE SPAM! A good filter can reduce the amount of SPAM getting through
to the end user (you) by 80% - 90%. But it is a constant battle. Our SPAM filter
uses a three prong approach to identify and eliminate unwanted emails.
- It looks for combinations of certain characteristics, i.e., multiple font sizes,
colored text, key words in the email's subject and body, etc.
NOTE: These characteristics are constantly being updated and fine tuned.
This will have the most noticeable effect on your In-Box. A score is given to each
of the SPAM-like characteristics an email contains. If the total score is above
a preseet level, the email is flagged as SPAM, but usually delivered to the end
user. A flagged email will have it's subject line altered as follows.
---SPAM--- Score/Req: 5.7/4.0 - Lowest Cost for Meds on the Internet
In this example, the original subject line was "Lowest Cost for Meds on the Internet".
The rest was pre-pended by the SPAM filter. You will only see this happen to the
subject of the email it's total score is over the preset level. In this example,
the email had a score of 5.7 while the preset level is 4.0.
Sometimes the SPAM filter will delete a flagged email instead of delevering it.
This happens when the email's total score is above a second, much higher, preset
level (8.0). It is reasoned that any email with a score this high, will never be
a "false positive".
- The use of global and self generated black lists. If the sending server is on a
black list, it's emails are automatically rejected.
NOTE: A black list is an archive of email servers that are known to spread SPAM
and any email server known to allow other email servers to anonymously relay through
them, thus giving SPAMer's a way to hide their true identity.
- Heuristic learning: By giving the SPAM filter examples of known SPAM and known non-SPAM
emails to analyze, it can then teach itself how to better identify SPAM.
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Stopping False Positives
There will always be some "false positives" (a non-SPAM email flagged as being SPAM
and some "false negatives" (a SPAM email that makes it through without being caught).
If you don't want to see these emails in your In-Box you can set up a "mail rule"
to automatically delete them. But to prevent accidentally deleting any "false positives",
it would be better to have all flagged emails automatically move to a folder named
SPAM. Then you can give the flagged emails a once-over before manually deleting
them.
Sometimes email from legitimate sources get flagged, even though, these sources
should know better and make sure that their emails do not contain so many SPAM-like
characteristics. The main reason for a "false positive", is an email being sent
to multiple recipients. It is common for SPAM to be sent to 10 or more people at
once. This one characteristic can easily cause an otherwise normal email to score
over the preset level. There have been emails from banks, insurance companies, investment
companies, and mailing lists get flagged for this. If you don't receive an expected
email, let us know about it and we will add the sender's email domain to our white
list ( an archive of email domains that bypass the SPAM filter).
Of course, this also happens every time Uncle Joe or Aunt Mary get a new joke, or
baby picture, that they want to share with everyone in their address book.
What can you do to cut down on the number of "false positives"? Set your email client
to send all emails as "Plain Text". Also, you should request others to use "Plain
Text" when sending emails to you. An email may not be as interesting to look at
if you don't use different font sizes and colors, or a stylish stationary border,
but it will be smaller and transfer much faster to its destination.
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