Imap password MTA option

BURL MTA options:  (string)
In order to perform an IMAP BURL operation, the  SMTP SUBMIT server has to have the ability to log in to the IMAP server as the submit user. The  MTA option specifies the password to use for such operations (and of course must match the password value set for the    account). This option has no default.

See also:
 * imap_username MTA Option
 * BURL MTA options
 * SMTP SUBMIT servers
 * submituser Option
 * BURL_ACCESS mapping table