[exim] SMTP AUTH with Exim as a client

Hello,

I want my Exim server to relay mails through a host requiring authentication (PLAIN or CRAM_MD5). But I don't see how to set it up.

Here is what I came up with so far:

relay_smtp:
driver = manualroute
transport = remote_smtp
route_list = * my.relayhost.com

remote_smtp:
driver = smtp
hosts_require_auth =my.relayhost.com
hosts_try_auth = ???

Where/how do I specify the login and password to use to authenticate ?

Thanks.

Christian