SMTPAUTH.TAB

 "username"[TAB]"password"[TAB]"permissions"[NEWLINE]

is used to permit SMTP clients authentication with protocols PLAIN, LOGIN, CRAM-MD5 and custom. With custom authentication a file containing all secrets (username + ':' + password) is passed as parameter to the custom authentication program which tests all secrets to find the one matching (if exist). For this reason it's better to keep the number of entries in this file as low as possible. Permissions are a string that can contain:

M

open mailing features

R

open relay features (bypass all other relay blocking traps)

V

VRFY command enabled (bypass SERVER.TAB variable)

T

ETRN command enabled (bypass SERVER.TAB variable)

Z

disable mail size checking (bypass SERVER.TAB variable)

S

ease SSL requirement for this user (bypass the ``WantTLS'' mail config variable)

When PLAIN, LOGIN or CRAM-MD5 authentication modes are used, first a lookup in 'MAILUSERS.TAB' accounts is performed to avoid duplicating information with 'SMTPAUTH.TAB'. Therefore when using these authentication modes, a user must use the full email address as username (the : separator is permitted instead of @) and his POP3 password as the password. If the lookup succeeds the 'SERVER.TAB', the 'DefaultSmtpPerms' variable is used to assign user SMTP permissions (default MR). If the lookup fails then 'SMTPAUTH.TAB' lookup is done.