Spam Checking  As mentioned on the smtp checks page, FastMail
performs many checks at the time an email is received to stop
spam. While these tests are very effective, they can't stop all
spam, and some still enters the FastMail system.  After FastMail
receives the email, we perform a number of checks based on the
content of the email to try and determine if the email is spam.
These checks are controlled by the settings on the Advanced ->
Spam/Virus protection screen.  'Spam Protection' Radio Buttons
Unsolicited Commercial Email ("spam", or UCE) can be a major
problem making it difficult to sort out your important emails
from junk mail. However, spam can often be identified by looking
for telltale signs such as mention of pornography, formatting
used by certain bulk-email software, and the presence of known
spam servers in the headers. By enabling the spam protection
option, FastMail automatically searches for these signs and
performs various actions depending how 'spammy' the message is.
The following leve