hi, > http://ftp.wl0.org/official/2.1/RPMS-rhel3-i386/postfix-2.1.5-4.rhel3.i386.rpm This RPM doesn't support TLS. To obtain RPM that supports TLS, it should Bild it from following SourceRPM. http://ftp.wl0.org/official/2.1/SRPMS/postfix-2.1.5-4.src.rpm The method of obtaining RPM that supports TLS is as follows. rpm -ivh http://ftp.wl0.org/official/2.1/SRPMS/postfix-2.1.5-4.src.rpm cd ../SOURCES export POSTFIX_TLS=1 sh make-postfix.spec cd ../SPECS rpmbuild -ba postfix.spec Tatsuo Sumiguchi