[exim] EHLO responses

We seem to be experiencing issues with some groupwise servers authenticating
with us.

On a couple of other email servers I've seen :-

250-AUTH=LOGIN PLAIN
250-AUTH LOGIN PLAIN

Exim only has the :-

250-AUTH LOGIN PLAIN

Is this something that can be turned on for Exim ?

I seem to recall there was a switch on postfix to do this.

-Andy-