There are a couple ways of doing this as long as the names are in your contacts. Click on the 'To:' button and a list will come up. Double clicking any name will add it to the To list. Also you can type in the names separated by a comma or semi-colon and Mail will look them up in the contacts list. If you type in just a first or last name and there are more than one possibility in your contacts, WM will offer a list of possible emails for you to choose from. This last bit won't happen until you hit the send button. You can also add more than one auto complete address (the last 29 names you've sent email to) by comma/semi colon separating the names.
thanks. wow that is easy. wish i'd known that. but another thing is that you know how when you start to type in an address and it fills it in for you? it is SO erratic. sometimes it does, sometimes not. what's up with that? and sometimes it will give me every name except the one i want, even if that one is one that i email frequently!
The auto complete feature uses a list of the last 29 names you've emailed to. This list includes people you reply to, so a name can get there even though you didn't actually type the name into an email. This list is kept in the registry. If you start typing a name and it offers the wrong name, just keep typing the correct name. If it is one of the last 29, it should offer it when it is the only (or at least the most recent of the possibilities) choice left.