MailEnable Features - Anti-spam & Security
MailEnable includes powerful anti-spam and security features to help keep
your data secure, your server running smoothly, and your inbox free from junk mail.
Bayesian filtering is a method of spam prevention. It operates by rating the probability
of incoming mail being spam by looking at words or character strings contained in
the email as well as the entire context of the email. Bayesian filters can be 'trained'
to identify spam by building up libraries of 'good' and 'bad' mail (spam). There
is also the ability to "auto-train" the Bayesian dictionary. This means the filter
is continually improving by 'learning' to identify spam and good mail based on emails
that are passing through the server.
Reverse DNS Blacklisting
Reverse DNS Blacklisting allows you to validate those sending mail against a list
of potential spammers. You can select which Real Time Blacklists (RBL's) providers
you want to use. You should enable only the providers that you need, as this does
impact on performance. You should also review which providers are most appropriate
by reviewing their web sites.
System Administrators can configure global thresholds for message throughput. Administrators can save server-wide settings that limit the
number of messages sent by a user.
These settings can be overridden as required on a per postoffice or mailbox basis. By default, users are capped at 100 messages per hour.
MailEnable can also permanently block IP addresses if they issue too many invalid commands to the server. MailEnable can lock out
accounts after too many failed password attempts. MailEnable services maintain a list of IP
addresses and record any significant activity. This record can then be used to determine whether the source addresses have violated a security
policy and should be temporarily blocked. As an example, an IP address that is connecting and attempting to spoof user accounts might be blocked
for an hour as a means of protecting password dictionary attacks.
Domain Keys (DKIM)
MailEnable's Domain Keys (DKIM) implementation provides inbound validation and outbound
signing of messages. The extensive filtering provided by MailEnable allows you to
discriminate messages according to their domain key validation. Administrators can
either use inbuilt simple criteria or tailor complex scripts according to filtering
URL Blacklist Content Filtering
The MailEnable SMTP Connector scans the content of messages as they are received
and can identify whether the contents of the messages contain offensive URLs by
looking up their IP address against DNS blacklist providers.
Use message filters to search messages for words or phrases and delete or quarantine
them before they are delivered to the user. Mark messages as spam so that they are
placed directly into the recipients Junk Mail folder.
Filters can also be configured to move or delete messages based on content and much
Sender Policy Framework (SPF)
Sender Policy Framework (SPF) prevents the 'spoofing' or forging of mail addresses
and makes it easier to identify spam, worms and trojans.
SPF requires a DNS record to specify which machines are authorized to transmit mail
for that particular domain. Therefore the mail server receiving mail can determine
whether a message came from a domain other than the one claimed by the sender.
Secure Data Transmission
MailEnable services all support SSL to protect sensitive data as it is accessed, and the
SMTP service provides outbound TLS/SSL support, allowing the secure encrypted
transmission of messages to remote SMTP servers.
Without relay control, spammers can utilise your server in order to send out their
junk mail, making it look as though you were the origin of spam. MailEnable has
inbuilt relay control that prevents your server being used as a relay for spam.
As well as supporting an impressive array of third party plug-in scanners, MailEnable
includes a pre-configured installation of ClamAV.
Compatible with 3rd Party Spam Filtering
MailEnable can also work in conjunction with various third party anti-spam applications.
End User Blacklisting And Whitelisting
MailEnable allows whitelisting to occur as messages arrive via SMTP.
This prevents messages from these domains from being delayed by greylisting. This feature
can be enabled or disabled as required.
Similarly, end users are able to reject messages from a given domain
or user at the SMTP level. A list of blacklisted email addresses and domains can be
configured via the webmail client. When a blacklisted sender attempts to send the message,
the SMTP connector will immediately refuse the delivery attempt.
Greylisting helps reduce spam by delaying messages for a short period of time when
the sender is not someone who has recently sent to that destination. A large percentage
of spammers do not retry sending a delayed message, but normal mail servers will,
so the message will come through on the next attempt.
for a full list of features.