Creating links of email type is very simple. It must be mentioned that when you put a email's link on a public page, is very easy for a expert to find it and use it later to send spam messages.
A different way, which lowers the risk of spam, is the implementation of an e-mail form in the content of your page.
If you want someone to write you an email the best way is to put a link with your email and a pre-established subject.
<a href="mailto:firstname.lastname@example.org?subject=Questions" title="">Questions here</a>
In case the subject is not enough and you want yo add something else in the email's content , you can do it with the help of the next code:
<a href="mailto:email@example.com?subject=Questions&body=Write here if you have questions" title="" >Questions here</a>