I have some issues with configuring clients (Outlook - smtp server cannot be configured - SSL_accept error) with our Virtualmin server.
I added the following lines to main.cf to disable the insecure TLS/SSL versions (is this correct, should I add other configuration?):
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, TLSv1.2
smtpd_tls_protocols= !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, TLSv1.2
smtpd_tls_mandatory_ciphers = high
Testing https://en.internet.nl/ shows that the Cipher is EDH-RSA-DES-CBC3-SHA.
Can you please let me know how to change the ciphers to the most secure ones (where is the configuration file where the ciphers are declared/defined)?