Fastmail made many security changes in July, 2016. See:
You only need to worry about the server names used by email client to send mail (SMTP) or read mail (IMAP or POP).
The nameservers are automatically found using a DNS search when another email system tries to send you a message, and at this time the nameservers for the fastmail.com domain (and I assume all Fastmail-owned email domains) are currently :
- fmns1.messagingengine.com
- fmns2.messagingengine.com
For your own domains, the
instructions still direct you to point your domain to the following nameservers (if Fastmail is hosting your domain):
- ns1.messagingengine.com
- ns2.messagingengine.com
Bill