New comment by nmeum on mblaze repository

https://github.com/leahneukirchen/mblaze/pull/173#issuecomment-605981282

Comment:
> I think alternate-mailboxes should just contain the addresses.

Good to know, but the `Local-Mailbox` should definitely contain a valid RFC 5322 address, or at least mine does. In general, it might makes sense to use this as is and improve it later on when tooling around RFC 5322 has improved? idk.