mail() and security

[Anon]

I have a form which the user can complete, part of this form contains an input $Email.

I then send the results of the form using mail() to the address $Email.

What do I have to do to check the value of $Email to ensure it is not passing a dangerous command to sendmail. Or does the Mail() function take care of this?

[alfoxy]

i use this

// check the validity of email
$valid_email = "/^{([a-zA-Z0-9.-_]+)@([a-zA-Z0-9-]+.[a-zA-Z0-9.]+)$/";} // valid email attributes [e-mail]
if( preg_match($valid_email,$email))
{
// valid email so do nothing or prompt for email again
}
else
{
// send email here
}

Al