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Tip on improving filters for junk/spam emails
Upon installation, Xeams will block
most junk messages sent to your server. However, you can take several steps to make the filtering better.
The following section lists some tips.
Ensure Xeams is the first server in the chain -
Often administrators use a combination of email filtering software to block junk messages.
It is very important that Xeams is the first server to receive email from the Internet.
Many filters in Xeams are based on IP address and Xeams will not be able to use these
filters if every incoming message appears to come from another SMTP server sitting in
between the Internet and Xeams.
Add an SPF record for your domain -
An SPF record prevents email forgery.
Send out-bound emails through Xeams -
Besides filtering inbound messages, consider sending outbound emails through
Xeams as well. The adaptive filters in Xeams will learn from these messages.
Imagine the following scenario
- John@YourCompany.com sends an email to Mary@ABusinessPartner.com
- If this out-bound message goes through Xeams, in-bound messages from Mary@ABusinessPartner.com
will automatically get negative scores preventing her messages from getting tagged as junk.
- Check the reason for spam - Every email contains a reason explaining how
Xeams assigned a score to it. It is important that you check the reason for any email that is
incorrectly marked and correct the problem.
Click Message Repository
on the main menu to view existing messages and then hover your mouse over the reason link.
- Mark emails correctly - If you see a message incorrectly tagged
as spam or good, mark them appropriately. Marking an email updates several filters and prevents future errors.
- Use Spam Simulator - Use spam simulator
to fine tune the rules.
- Avoid white/black listing entire domains - Think twice before white listing
entire domains, particularly if they are popular domains like Hotmail.com, Yahoo.com or GMail.com. White listing takes
the score of the message too far in the negative zone and therefore, scores from other filters do not matter.
One common mistake many administrators make is that they white list their own domain name. Since email forgery is very common,
every forged message will get through if the domain is white listed. Click here
for more details on this topic.
- Consider creating a temporary filter -
Create temporary filters for innocent emails.
- Consider adding content filters - Create subject and body filters with keywords that a spammer would not know.
These keywords should have a negative score. For example:
- Your zip/postal code
- Street name
- City/town you live in
- Your phone number
- Products you deal with
Avoid aggressive scoring -
Xeams uses a combination of rules to determine the message category. If it matches a rule with a
high value, weights added by other rules in the system will no longer matter.
As a rule of thumb, avoid giving a score higher than 300 to any rule.