Worth following all the instructions on https://www.fastmail.com/help/receive/stopspam.html https://www.fastmail.com/help/receive/stopspam.html I found pointin

Worth following all the instructions on https://www.fastmail.com/help/receive/stopspam.html https://www.fastmail.com/help/receive/stopspam.html I found pointing my MX records straight at Fastmail helped a lot with spam. See "If you use your own domain" in those instructions.