Hello! I tried to configure Mailgun using AdminFE and config.exs, but it returns this on verification letter:
akkoma-server-1 | 20:17:14.831 [warning] Description: 'Authenticity is not established by certificate path validation'
akkoma-server-1 | Reason: 'Option {verify, verify_peer} and cacertfile/cacerts is missing'
Could it be possible, that your server is missing a package containing ca certificates? What operating system are you using? If you try to access mailgun via curl on your server, does it work?
Just fixed this exact error on smtp with Migadu, by changing starttls Mode to :never
It was :always
Well, I asked more knowledgeable friends that do this for a job and they said change that, and it worked.
Unsure if related to your mail setup, but sharing just in case.