Sorry for the long delay in answering.

I did not mean to "get rid of a local keyring". I am just wondering, what we want / expect the user to do in the situation, where a mail with a public key arrives?

1. Ignore the key unless the user is experienced and knows and cares about managing public keys (because we favour WKD)
2. Update the key database in case the key is not stored yet
3. Always take notice that a public key is attached so the user can decide what to do
4. Get educated about encryption
5. ???

The design is a result out of this decision. So, what do we want to achieve?

Ok, when saving a local copy of the key is not our intention, then the proposed solution obviously is wrong :)

Ok, I think I get the idea.

For the wording in the mails I would suggest something like:
"This is an automatically generated email. The purpose of this email is to:" and then add the purpose of the mail, so for the