YLB Score › The checks, explained › Part II, Will their message reach you?

The fake-mail filter

There is a public setting that tells the world's mail servers what to do with a message that claims to be from you but is not: let it through, send it to junk, or refuse it. Think of it as a filter for fakes. Most small firms have never fitted one.

Without it, a criminal can send your clients an invoice in your name, and it lands in their inbox looking exactly like yours. Fitted and set to watch is a start; set to refuse is where you want to be.

Worth about 4 points of your 100 for a typical businessAbout 1 hour, by whoever runs your email

See for yourself

Type your domain into dmarcian's checker. It tells you whether the filter is fitted and which setting it is on.

• Free tooldmarcian's record checker

How to fix it

1. Fit the filter set to watch, and read the reports it sends you for a fortnight to confirm your real mail passes.
2. Move it to send fakes to junk, then to refuse them.
3. Your email provider or your domain provider can do each step; it is one line each time.