Anti-spoofing for Custom Domains (SPF, DKIM & DMARC)
Does mailbox.org offer anti-spoofing options for custom domains? I can find no information about this on the help pages. Other privacy-oriented providers, e.g. protonmail, do offer this (see here: https://protonmail.com/support/knowledge-base/anti-spoofing/).
Mailbox.org should make information about SPF, DKIM and DMARC easy to find.