Most email programs allow you to automatically attach a 'signature' line at the end of the email messages you send.

Usually the signature lines include your email address, your company name, and in the case of business mail, your phone number. Information that might be valuable to the recipient.

Some people have taken the signature line a step further - by using it to include ads for products they sell. Usually a short sales pitch for the product and a link to the order form.

While this might sound like a good way to gain a few extra orders, it actually isn't. In fact, it can cause your email to be deleted by spam filters.

Just this week a client sent me a message I never received. Truth is, the email did reach me, but because the message included an ad in the signature line, my spam filter deleted it - along with the 400+ real spam messages I get each day.

After I discovered the problem, I advised the client that much of the email she was sending to others was probably being deleted by their spam filters - simply because she included the signature line ad.

Moral: If you want your email to get through, be sure it doesn't include elements associated with spam - else you risk having your mail shredded by the filters.