POP3(8)                                                   POP3(8)

     NAME
          pop3, imap4d - Internet mail servers

     SYNOPSIS
          upas/pop3 [ -d debugfile ][ -a mailbox ][ -r peeraddr ][ -t
          tlscertfile ][ -p ]

          upas/imap4d [-acpv] [-d smtpdomain] [-s servername]

     DESCRIPTION
          These programs support remote access to mail across the
          Internet.  All expect the network connection to be standard
          input, output, and error.  They are normally started from
          scripts in /rc/bin/service (see listen(8)).

          Pop3 provides access to a user's mailboxes via the POP3 pro-
          tocol.  The options are:

          -d  create debugfile and write debugging output to it

          -a  causes pop3 to assume that it already authenticated and
              to read mailbox immediately

          -r  causes pop3 to create the file
              /mail/ratify/trusted/peeraddr#32 to allow subsequent
              SMTP sessions from that address.  See ratfs(4) for
              details.

          -t  get the local TLS certificate from the file tlscertfile.

          -p  allow passwords in the clear for authenticating the con-
              nection

          Imap4d provides access to a user's mailboxes via the
          IMAP4rev1 protocol.  Only files rooted in
          /mail/box/username/ are accessible.  The list of subscribed
          mailboxes is contained in
          /mail/box/username/imap.subscribed, and initially contains
          only INBOX, IMAP's name for the user's mailbox.  A shadow
          file, mailbox.imp, is created for each mailbox examined.

          Imap4d's options are:

          a   Assume the user is already authenticated.  By default,
              the user must authenticate using CRAM-MD5 or
              securenet(8) challenge/response authentication.

          c   Allow plan 9 challenge response authentication.

          p   Allow login authentication.  This option should only be

     POP3(8)                                                   POP3(8)

              enabled for servers using an encrypted connection, such
              as SSL, and when enabled, all non-encrypted connections
              should be disallowed.  Imap4d does not enforce this pol-
              icy.

          v   Turn on verbose output to the debug file.

          s   The server's name.  If none is provided, cs (see ndb(8))
              is queried or /env/sysname is used.

          d   The local mail domain.  Defaults to the server /env/site
              in the mail server's domain.

          For both imap4d and pop3, the password used to authenticate
          the connection is the APOP secret held by keyfs(4) running
          on the authentication server.

     FILES
          /sys/log/imap4d                   debugging output
          /mail/box/username/mailbox
          /mail/box/username/mailbox.imp
          /mail/box/username/imap.subscribed

     SOURCE
          /sys/src/cmd/upas/pop3
          /sys/src/cmd/upas/imap4d

     SEE ALSO
          aliasmail(8), faces(1), filter(1), mail(1), marshal(1),
          mlmgr(1), nedmail(1), qer(8), rewrite(6), send(8), upasfs(4)

     BUGS
          Usually messages flagged for deletion with DELE are not
          actually deleted until the client sends a QUIT command to
          end the conversation.  Pop3 implements a non-standard com-
          mand SYNC that deletes messages flagged for deletion without
          ending the conversation.