Locates mail drops when mail is received, and maps user names to their external form when mail is sent. The format of the database file (e.g., /etc/userdb ) is:
user:maildropuser@hostuser:mailname[email protected]
As a shorthand, if all users in a database should have their domain name changed when mail is sent, use:
:default:mailnameexternal.domainuser1:maildropuser1@hostuser2:maildropuser2@host
You build the database using the makemap (1) program:
% makemap btree/etc/userdb</etc/userdb
Berkeley database ( btree class) support is required.