RHEL/CentOS 6.5 will support ECDHE Fedora currently makes the turnaround

no wonder that i burned down many hours: https://bugzilla.redhat.com/show_bug.cgi?id=1019390 https://bugzilla.redhat.com/show_bug.cgi?id=319901#c108

recent dovecot with also support older clients but perfer best possible encryption for modern ones

ssl_prefer_server_ciphers = yes ssl_cipher_list = EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:RC4:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!SSLv2:@STRENGTH

the same for Apache:

SSLHonorCipherOrder On SSLCipherSuite EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:RC4:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS