Enable resending one message to multiple recipients
Occasionally it is desirable to resend a message to multiple recipients so that they see all recipients, too. Currently we're sending one distinct message per recipient, so none of them knows who gets the same message.
We should enable the first possibility without breaking the second one.
My best idea is to send a discinct email for each x-resend-line but to use all addresses from that line in this one message.
Example 1:
x-resend: me@example.org
x-resend: you@example.org
Example 2:
x-resend: me@example.org you@example.org
In example 1 the recipients would receive each their own message without any hint whoever else got this message.
In example 2 one message would be addressed to (and optionally encrypted to) both recipients so they could see and reply each another.
This feature would enable to integrate addressing as Cc, too (#105 (closed))
If we do this we should do it now, because it changes the usage of the resend-command. After releasing 3.0 we'd have to wait for 4.x to release this, according to the semantic versioning.
Any opinions?