Yes, but. Because of the ever-present threat of spam, we monitor email usage very closely. Therefore, you should expect an amount of scrutiny directly proportional to the volume of email you send.
It is also very important to be aware of potential vulnerabilities introduced by email-enabled web pages. In particular, generic PHP "feedback" form scripts have proven to be very popular targets for spammers, who can find and exploit them automatically. You should be extremely cautious, and make sure that any email-enabled web sites you create are safe from exploit.
We will hold you responsible for email activity caused by your site, whether you intended to allow it or not. If a spammer exploits a script on your site to send spam, we will have to clean up the mess. At a minimum, that will probably entail temporarily disabling your site, and it may result in additional charges for you.