From the guide:"All forms of personal information including address, phone numbers, etc. should not be publicly posted on the forum, for the safety of our forum users. Private mail should be used to communicate this information."
This statement applies to email addresses. Don't put them in your posts. You can put one in your profile, and logged on forum users will be able to see it and email you.
The safest method is to use Private Messages. There is an option to receive an email notice when you get a private message, which makes it almost the same as sending emails directly, and protects the email address. If you need help with your profile settings, just ask.