Remove private information on copy when alias is linked to multiple mailboxes

[TheFou]

Hi,
When I send / reply to an email from a contact which is proxied through SL, and when the relative alias is linked to 2 or more mailboxes, the other mailbox(es) receives a copy of the email, with my real email address which sent the email.

I find it to be a privacy concern, and it kind of defeats the purpose of SL.
It makes my real email address, which I don't use for anything else than through SL aliases, apparent to other services like gmail.
I don't want this email address to appear anywhere, so that it can't be scanned or reused by any service, or malware, or anything.

Please consider removing this information from the email copy, the alias email is sufficient in my opinion.
It would also be nice to be able to disable this feature (the copy email) on a global and per-alias basis.

Regards.