User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.8.1) Gecko/20061010 Firefox/2.0 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.8.1) Gecko/20061010 Firefox/2.0 I have collegues with whom I should really only communicate with using secure mail (S/MIME), most of the rest of the world however either do not have certificates or the communication topics are generally unimportant. It should be possible to define that mails to specific contacts should always use a default security setting - for instance always encrypt using a certificate. If sending a mail to more than one recipient where only some have the security setting in the address book then ask if the others should also receive the mail encrypted or if the mail should be sent unencrypted. Reproducible: Always