MS Outlook stops working with sendmail/dovecot after upgrading to RHEL 6.5

Issue

• Why mail client MS outlook 2013 not working with sendmail smtp server after upgrade to RHEL 6.5 ?
• Below error message appears.

Send test e-mail message: Your server does not support the connection encryption type you have specified. Try changing the encryption method. Contact your mail server administrator or Internet service provider (ISP) for additional assistance.

• Other email clients work & also downgrading the openssl package to openssl-1.0.0-27.el6_4.2 works