Hmm, am I seeing this correctly that the system does receive emails only via IPv4 and no IPv6? This would make the SPF check somewhat misleading as it only checks one option.
You are correct, the mail server is currently configured to only receive emails via IPv4. This setup is not uncommon as most major email providers have IPv4-only MX records (with Gmail and Yandex Mail being rare exceptions that support IPv6).
It might be a good idea to provide a different email address whose mail server explicitly requires IPv6. I'll think about it. Thanks for bringing it up.
It might be a good idea to provide a different email address whose mail server explicitly requires IPv6. I'll think about it. Thanks for bringing it up.