[imp] Identiies vs Aliases

[Simon B]

Hallo

What is specific purpose of these entry fields in the Mail/Personal
Information preferences?

Your alias addresses: (optional, enter each address on a new line)

Addresses to explicitly tie to this identity: (optional, enter each
address on a new line)

I added some email addresses (both as created identities and addresses
I can receive but do not necessarily want to send from) to both, in
the hope of allowing me to reply-as from Nine, but the only effect
that I see, is that putting an identity address means that replying
removes the identity..

For example, if my default identity is simon at example.com and I have an
identity as simon at example.net, putting simon at example.net into those
boxes, means that when an email is addressed to simon at example.net, the
reply comes from the default identity.

Exactly the opposite of what I want...

Thanks.

Simon