Some mails never reach the inbox; I wasn't able to receive GitHub verification emails in particular. I'm curious, does GitHub connect to the bridge in practice, or it doesn't show any sign of attempting to send email there at all?
Another thing I notice is both `uid.ovh` and `nmail.li` don't have DNSSEC enabled. I have no idea whether it breaks anything, but who knows what other servers might additionally check; perhaps enabling DNSSEC would be useful for the bridge in particular.