cage cage authored Aug 07, 2024 and Kilian M. Haemmerle committed Aug 07, 2024

Add dynamic variable `*message-id-generator*`
which is set to `:uuidv7@domain` by default.
This can be changed e.g. to `nil` to inhibit
message-id addition to emails.

Message-id generation restart options are:
- send-without-message-id
- use-local-hostname
- use-custom-domain-part
- use-custom-message-id

The symbols are also exported.