In order to fix the recently issue on Outlook express outgoing problem, relates to the following change in cPanel version 66:
Please follow being step to fix it.
Fixed case CPANEL-11108: Remove Triple DES from default cipher suite.
You can browse to "WHM >> Exim Configuration Manager >> Advanced Editor" and change the "tls_require_ciphers" value to the following value that was issued by default in cPanel version 64:
However, keep in mind this is unsupported and not recommended due to the negative impact on the server's security. Instead, the recommended solution is to upgrade systems using Windows XP to a supported OS (Microsoft no longer provides security updates or technical support for the Windows XP operating system).
If you're on our Managed Service, please submit a ticket to Support and we will fix it for you.
HaBangNet Server Admin Team