Distinguish between a Subscription's key and a random keyring entry in check_keys notification
At the moment keys check notifies about all keys in your keyring.
The output should be split in 2 sections: Keys of subscriptions and all other keys in the keyring. This way an admin can easily identify if something urgen needs to happen.
For a list that e.g. is an address of a project, that is especially used to communicate with addresses outside of the list, the majority of the keyring might be random keys that were used once in a while, but are not relevant for the list to function.
refresh_keys should still refresh all these keys, I don't think keys check should report anything about them, as otherwise lists as decribed before will always get a huge list of expired/revoked keys.
As noted in #227 (closed) the output must also be more descriptive and e.g. divided by keys for subscriptions and keys not related to a subscription. And then we could only send out the check email if any of the subscriptions is affected.