dak has started to sign (some) outgoing mail using PGP/MIME. Theseinclude upload notifications (accept or reject mails), processing .dak-command files (e.g., DM permissions), bug closures and some more. Thekeys used can be found on [1] under "Upload Processing Keys", but mostconsumers probably do not need to check these.
If you maintain a service that consumes mails sent by dak, please checkthat it does not get confused by the added signature.