if-then rule for e-mail encryption
In UTM 9.2 SPX Encryption will be added.
At the moment eMails wont be delivered if you use SSL/TLS and the receiver doesnt support encryption.
My suggest is to force SPX Encryption if SSL/TLS doesnt work, with automatically notification to the user "hello, mail was sent with pw "xyz" to recipient "abc", pls provide pw to recipient and note that recipient doesnt support encryption". or so.