I'm posting this becuase I've seen experienced board users who
don't know this.  Please chime in if I get anything wrong.

For each TER handle, a user can have multiple aliases.

When you click on a post to read it, you will see the poster's
name in the upper left corner of the post.  If you see a little
yellow envelope to the right of the name, then that is the
person's TER handle.  You can click on the envelope to TER mail
that person.  This post is done with my TER handle.

If there is no envelope (like the example I've linked below)
then the poster is using an alias.

Note that reviews and TER mail can only be sent to a TER handle,
not an alias.  Also, although you can send TER mail to any TER
handle, the receiveing person can't read their mail unless they
are a VIP.

hope that helps,
fr