Yes! To send an email to another member, you can either locate the member you want to contact on the member list, or click the button on any post made by that member.
This will usually open a page that contains a form where you can enter your message. When you have finished typing your message, press the [send email] button and your message will be sent instantly. Note that for privacy reasons, the email address of the recipient is not revealed to you during this process.
Note that if you can not find an email button or link for a member, it either means that the administrator has disabled email functions for this forum, or that the member in question has specified that they do not wish to receive email from other members of the forum.
Another useful email function is the ability to send a friend a link to a thread you think they may find interesting. Whenever you view a thread, you will find a link somewhere on the page which will allow you to send a brief message to anyone you like. Your referrerid is added to the link you send, so if your friend registers on this forum as a result of viewing the link you sent to them, your referrals total will automatically be credited!