9.1.2. Sending

These settings define how Enigmail must behave when sending secured mail.
You can jump to this settings window also by selecting the menu command OpenPGP → Default Composition Options → Send Options... in the Message Composition window.

Add my own key to the recipients list tells Enigmail, when sending encrypted messages, to encrypt with your own public key (as specified in the current account settings) as well as with the recipients' public keys. This is required to allow you to decrypt your own messages you have encrypted. Therefore, you should leave this option enabled.

If you use HTML to compose email messages, messages signed with the inline PGP standard (the default in Enigmail) need to be re-wrapped before they can be sent in order to avoid invalid signatures. However, re-wrapping can cause the text to look differently from what you have typed. We recommend you leave enabled the option Re-wrap signed HTML text before sending, unless you have problems caused by re-wrapping.

Usually, OpenPGP does not allow you to encrypt message with keys that you do not trust. The option Always trust people's keys overrides the trust level of other people's public keys so that you are able to encrypt with untrusted keys. You should leave this option enabled.

Don't warn about empty subject line prevents Thunderbird / SeaMonkey from complaining about an empty subject line when composing a message.

Always confirm before sending prompts you a confirmation dialog before sending any message, so that you can check the signing, encryption, and S/MIME status. It is advisable to turn off this option if you send S/MIME signed or encrypted messages from time to time.