Replace {domain}
with your domain:
# Allows you to receive email at standard addresses, e.g. user@{domain}.
now dns add {domain} @ MX in1-smtp.messagingengine.com 10
now dns add {domain} @ MX in2-smtp.messagingengine.com 20
# Allows receivers to know you send your mail via FastMail, and other servers.
now dns add {domain} @ TXT "v=spf1 include:spf.messagingengine.com ?all"
# Allows FastMail to sign the mail you send so receivers can verify it's from you.
# This is important to ensure your message is not classified as spam.
now dns add {domain} mesmtp._domainkey CNAME mesmtp.{domain}.dkim.fmhosted.com
now dns add {domain} fm1._domainkey CNAME fm1.{domain}.dkim.fmhosted.com
now dns add {domain} fm2._domainkey CNAME fm2.{domain}.dkim.fmhosted.com
now dns add {domain} fm3._domainkey CNAME fm3.{domain}.dkim.fmhosted.com
# Allows email clients to automatically find the correct settings for your account.
now dns add {domain} _submission._tcp SRV 0 1 587 smtp.fastmail.com
now dns add {domain} _imap._tcp SRV 0 0 0 .
now dns add {domain} _imaps._tcp SRV 0 1 993 imap.fastmail.com
now dns add {domain} _pop3._tcp SRV 0 0 0 .
now dns add {domain} _pop3s._tcp SRV 10 1 995 pop.fastmail.com
# Allows CardDAV clients to automatically find the correct settings for your account.
now dns add {domain} _carddav._tcp SRV 0 0 0 .
now dns add {domain} _carddavs._tcp SRV 0 1 443 carddav.fastmail.com
# Allows CalDAV clients to automatically find the correct settings for your account.
now dns add {domain} _caldav._tcp SRV 0 0 0 .
now dns add {domain} _caldavs._tcp SRV 0 1 443 caldav.fastmail.com
now dns add {domain} _imap._tcp SRV 0 0 0 .
now dns add {domain} _pop3._tcp SRV 0 0 0 .
now dns add {domain} _carddav._tcp SRV 0 0 0 .
now dns add {domain} _caldav._tcp SRV 0 0 0 .
all of these are throwing errors: