Include List-Unsubscribe headers in DKIM and DomainKey signatures
I'm sending mails through mailgun.com via STMP and I add "List-Unsubscribe" headers to my emails prviding unsubscribe-email and -url (where appropriate).
As these headers (email and url List-Unsubscribe) are not included in the DKIM or DomainKey signatures, they are ignored by some mail services ...e.g. Gmail. :-(
Please include the provided List-Unsubscribe (and possibly other already existing) headers in the DKIM- and DomainKey signatues or provide an option to define which headers should be included. => X-Mailgun-Include-In-Signature header
Liam O'Boyle commented
Definitely useful if Gmail is ignoring unsigned headers.
Even better would be if MG's unsubscribe links could be used for unsubscribe themselves, rather than having to roll your own. It seems simple enough.