exim-3.21-3 is compiled without smtp authentication support # rpm -q exim exim-3.21-3 [root@clienthost /root]# exim -bP authenticator_list [root@clienthost /root]# exim -bP authenticators [root@clienthost /root]# It should be compiled in. This is a very commonly used feature. See http://www.exim.org/exim-html-3.20/doc/html/spec_35.html#SEC751 for the compilatiuon parameters.
[root@cyberelk /root]# /usr/sbin/exim -bP authenticator_list cram [root@cyberelk /root]# rpm -q exim exim-3.21-3 The binary is built with support; you need to add the configuration yourself.