sasl auth with exclusion for a relay host

Hi all,
I have an email server that has about 1 k users . There was no
authentication besides the "reply-to" auth ( done with
check_recipient_access and check_sender_access )

I decided to move to SASL auth but my server relays mail for another 3
exchange servers . Users on those M$ES are authenticated on their
servers but there's also a "reply-to" auth that i mentioned what means
that when they add an user , I have to add this user to my map too.

The question is - after I implement SASL and I will remove the
"check_(recipient|sender)_access" entries in main.cf - what will
happen with the relay hosts that i relay mail to ? My hosts that i
relay mail to are defined in transport_maps .

Will SASL prevent emails being relayed to theese hosts or it will pass
is through without an action ?

regards and thanks 4 your time.

--
Wojciech Ziniewicz
Unix SEX :{look;gawk;find;sed;talk;grep;touch;finger;find;fl
ex;unzip;head;tail; mount;workbone;fsck;yes;gasp;fsck;more;yes;yes;eje
ct;umount;makeclean; zip;split;done;exit:xargs!!;)}

--