For an article about “mastering email security,” this is missing an awful lot of recent email security developments like ARC, DANE, MTA-STS and TLSRPT while simultaneously spreading misinformation about the holy trinity of email security protocols. Impressive, I guess?

Edit: Oh wow, even from an email security vendor. They really didn't do their research. I definitely wouldn't trust them to protect my email security, partially due to them literally not supporting the necessary protocols to do so.