A bit like a television advertisement for a certain anti-dandruff shampoo, when you tell someone you have email or spam filtering they will often say ‘but you don’t get spam’, to which you reply ‘exactly’.
This is the unfortunate truth, anti spam filtering is a necessary evil, a cost that in an ideal world you wouldn’t have to bear but in order to avoid the near endless offers of pharmacy drugs, lottery claims, deposed dictators and general rubbish you need to make the investment in email filtering.
At it’s basic email filters do a couple of things.
- They compare originator email addresses with ‘blacklists’ to see if the domain is known for spam / infections. If it is then it’s marked as spam and not sent to the mail server.
- They also take the email and search for common ‘trigger’ words, these words are each given a points rating, so for example, ‘cure baldness’, ‘online pharmacy’ and ‘join millions’ would each get 5 points. If the system is set with a threshold of 14 points then that mail’s going into the spam folder. (if you were emailing Wayne Rooney he may well choose to mark the sender as safe but that’s his choice)
They type of filtering is up to you but they invariably fall into two categories, cloud based (hosted) or onsite systems. Both have advantages and cost variables but you need to ensure that the systems allow for the following at a minimum:
- Ability to review blocked messages (and release)- there is no guarantee that your client hasn’t gotten in there by mentioning too many trigger words.
- Ability to mark addresses as safe. Important if you get automated messages from web servers etc.
- Anti Malware and Phishing detection, stop the infections before they get anywhere near your firewall / server.
There are bells and whistles out there too, options can include:
- Email continuity where the filter stores a number of weeks history of normal emails so in the event your server goes offline you can access all your emails from the last x days from their web interface. This can tick a lot of SOX and compliance boxes.
- Spooling – in the event that your email server becomes unavailable you would ideally like the messages to queue at the filter until the server becomes available again.
- Custom rules – if you know that certain emails are not wanted you can improve the chances of catching them.
At the end of the day if you want to use your email for anything other than looking busy you need to have filtering, sucks but it’s true.