The current wording of the "If possible" option is hard to parse. I
suggest changing it to:
If possible (messages are sent without encryption if not all
recipients have a certificate)
or
If possible (messages are sent without encryption if at least one
recipient has no certificate)
Either "messages" should be capitalized or "Send" should not be
capitalized. Imperitive might be better than passive voice. (Send
messages without encryption if not all recipients have a certificate.
Disable send unless all recipients have a certificate.)
Do we really need the UI to support different identities for signing and
encryption?
