Spam Filtering involves a layered approach.
- QTH.com uses multiple methods to block spam, at the server level, including:
- The IP address of the sending mail server is checked against the current list of known spammers in the Realtime Block Lists (RBLs) from SpamHaus, Barracuda Networks, SpamCop and NJABL.
- Mail sent from unknown mail servers is temporarily deferred. This is known as Greylisting and is very effective in stopping spam, as spammers will rarely retry their spam message a second time (or they will be blocked by the IP RBLs by the time they try again). NOTE: Customers can disable Greylisting by logging into their cPanel control panel and clicking Greylisting.
- Dictionary Attacks are blocked. This means that servers trying to guess at email addresses will be stopped after a few wrong guesses.
- HELO is thoroughly examined. Servers delivering mail must send HELO before sending mail, must have a fully-qualified domain for the HELO, and the HELO must conform to RFC2821 standards.
- The FROM address is examined. It must be from a real domain name that resolves, and if the domain is hosted locally, the email address must exist.
- Executable file attachments are blocked, to help stop viruses.
- SpamAssassin checks the body of the message for very spam-like characteristics and blocks accordingly. This is not a strict check -- if you want tighter spam checking, this is done in your own cPanel control panel (see below).
- Each of our customers can enable SpamAssassin, at no cost, via our cPanel control panel, to be more aggressive in spam checking than our default server configuration provides. Customers can then also tweak how SpamAssassin detects and handles spam. IMPORTANT NOTE: Spam Assassin only works on Mailboxes (Email Accounts) on our server. It does not do anything if you are using Email Forwarding to forward your mail to another provider. In that case, you should be relying on the spam filtering of your own provider that you are forwarding mail to.
- Customers that are using an email program, such as Outlook or Thunderbird, can usually configure their email program to filter spam as well. Here are some links to help configure various email programs for spam filtering:
- For just $0.99/mo (up to 10 mailboxes) or $1.99/mo (11+ mailboxes), we now offer a 3rd party spam filtering service called SpamExperts. This is a very robust spam filtering service, which can also send individual users and/or a manager a summary email each day with a list of held spam and allows the release any of those messages with one click. Whitelists and Blacklists are configurable. A Two Month FREE trial is available, if you would like to give this service a try. Contact us to start the trial or CLICK HERE if you want to skip the trial and buy it right away.
