# Defining Alternate Mailboxes

If you get mail at more than one "mailbox," you'll probably want to tell MH about your alternate mailboxes. In other words, if you receive mail at more than one address on one or more computers -- but all the mail is put into a single set of mail folders -- then the other addresses are your "alternate mailboxes."

This can happen with a setup like the one in the Section Changing MH Directory Name, where Walt is getting mail from three accounts that all inc into the same set of folders. It can also happen when mail is forwarded from other accounts -- for example, with a .forward file under UNIX Sendmail, a `SET FORWARD` command under VMS Mail, etc.

Some good reasons to tell MH the addresses of these alternate mailboxes:

- The command repl -nocc me will know which other mailboxes should not get extra copies of a message.
- When you scan your folder, messages that you sent from any of those accounts will be marked `To:recipient` instead of shown as `From:` your other account.

Let's go on with the example of Walt, above. People can send mail to him at walt, project, and walter. But he receives and answers it all on the walt account. He should put this entry in the .mh_profile file on his walt account:

        Alternate-Mailboxes: project, walter

That entry may not be enough to catch all of the mail, though; the `Alternate-Mailboxes:` entry has to match the `From:` address exactly. Depending on Walter's computer, some of the mail he sends may have his full network address (like `walt@xxx.yyy.zzz`) in the `From:` header field. An asterisk (`*`) means "match all." So Walt may want to use this entry instead:

        Alternate-Mailboxes: project@*, walter@*

That matches any addresses that start with project@... or walter@.... Unfortunately, it also includes addresses that start with those words on other computers -- even if they're not his accounts. The following entry with his fully qualified hostname might be best of all:

        Alternate-Mailboxes: project, project@xxx.yyy.zzz,
                walter, walter@xxx.yyy.zzz

(You can continue an entry on another line by ending a line with a comma and indenting the next line with space or a tab.) Finally, if Walt reads mail while logged on to either of his walter or project accounts, he should put `Alternate-Mailboxes:` entries in the .mh_profile files on those accounts.