Sendmail Relay authentication

[Joey Prestia]

Hi,

I am administering a e-mail server running RHEL 5 with sendmail 8.13 and
using dovecot imap most of the users are going to need to be able to
send mail from their laptops and i have no idea what network they will
be utilizing. After looking through the Practical Guide to Red Hat Linux
I tried adding this to the sendmail configuration and users were
able to send but the users were unable to get any mail after i generated
~  a cert implemented the changes. How can I implement a secure form of
authentication that will allow my users to receive and only relay with
authentication?

  define(`confAUTH_OPTIONS', `A p')
  TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')
  define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5
LOGIN PLAIN')
  define(`CERT_DIR', `/etc/pki/tls/certs')
  define(`confCACERT_PATH', `CERT_DIR')
  define(`confCACERT', `CERT_DIR/sendmail.pem')
  define(`confSERVER_CERT', `CERT_DIR/sendmail.pem')
  define(`confSERVER_KEY', `CERT_DIR/sendmail.pem')
  define(`confCLIENT_CERT', `CERT_DIR/sendmail.pem')
  define(`confCLIENT_KEY', `CERT_DIR/sendmail.pem')


-- 
Joey