diff --git a/roles/sendmail/templates/sendmail.mc.j2 b/roles/sendmail/templates/sendmail.mc.j2
index e3d064d..f4d115a 100644
--- a/roles/sendmail/templates/sendmail.mc.j2
+++ b/roles/sendmail/templates/sendmail.mc.j2
@@ -17,6 +17,7 @@ define(`UUCP_MAILER_MAX', `2000000')dnl
 define(`confUSERDB_SPEC', `/etc/mail/userdb.db')dnl
 define(`confPRIVACY_FLAGS', `authwarnings,novrfy,noexpn,restrictqrun')dnl
 dnl #
+define(`confAUTH_REALM', `{{ mail_server }}')dnl
 define(`confAUTH_OPTIONS', `A p y')dnl
 TRUST_AUTH_MECH(`GSSAPI PLAIN LOGIN')dnl
 define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI PLAIN LOGIN')dnl