Configs in

/etc/mail/sendmail.cf


Queue in 

/var/spool/mqueue


Aliases are in 

/etc/mail/aliases


Apply new aliases

sendmail -bi  or newaliases


See how an address would resolve

sendmail -bv <address>


Stop and start sendmail on aix

stopsrc -s sendmail
startsrc -s sendmail -a "-bd -q30m"


Get the status of sendmail on aix

lssrc -s sendmail


Process the queue right now. Works also if not running in daemon mode

sendmail -q