When you have any kind of form on your site there is the possibility that automated bots may create entries and you will receive emails with jibberish as content.
In order to guard against this you should consider adding a CAPTCHA to the form.
A Captcha is a type of challenge-response test used in computing to determine whether or not the user is human.
It requires you to type in the letters you see, thus confirming you are a live person.
We can add a captcha to any form , and takes about 1 hour at our standard rates.