Help! Verizon/exim authentication

[R Ransbottom <rir@comcast.net>]

I am trying to set up exim 3.36 on woody to connect to a Verizon SMTP
server.  I don't know how to set up authentification.

Verizon advertises these AUTH's.

250-AUTH=LOGIN PLAIN
250-AUTH LOGIN PLAIN

I am using exim's plain authenticator.  This seems to mean that
every user must use the same email address to send mail--the AUTH
login needs to match to Email "From" address.  This doesn't seem
tidy is there another way?

Having an on-site mailserver is mandated for logging so having clients
talking directly to outgoing.verizon.net is not an option.

Thanks.

Be well,
rir