Security considerations when creating an email for

问题:

I know I have to consider about
mail header injection,

and are there more thing that
I need to know before I make form mail thing?

I want mail, and I feel that
I have to set up form mail thing
in my page, but I heard that
mail thing is dangerous if I do not consider all security things.

回答1:

1- avoid spam, use captcha or other thing to prevent spam.

the link talk about it : Are you human? (or How to prevent spam)

2 - Prevent Duplicate Submissions