This page provides details on advanced domain setup options in Fastmail, and is meant for more technical users. DNS is a complicated system that can break your website and/or mail delivery, so we strongly suggest that you do not make any changes to your DNS unless you have an understanding of DNS, or are following explicit instructions.
Looking for basic domain information or setup instructions?
Want more general information about how DNS works?
Full list of DNS records
This is the full list of DNS records we can publish for you. You can choose to disable any of these. The information is also available on the Settings → Domains screen, in the Show DNS Settings section.
All entries have a 1 hour TTL.
Websites
- Allows you to host websites at
http://{mydomain.com}from your Fastmail file storage. - CNAME
{mydomain.com}web.fastmail.com
Standard Mail
- Allows you to receive email at standard addresses, e.g.
user@{mydomain.com}. - MX
{mydomain.com}10 in1-smtp.messagingengine.com - MX
{mydomain.com}20 in2-smtp.messagingengine.com
Subdomain Websites
- Allows you to host websites at subdomains, including
http://www.{mydomain.com}, from your Fastmail file storage. - CNAME
*.{mydomain.com}web.fastmail.com
Subdomain Mail
- Allows you to receive email at subdomain addresses, e.g.
foo@user.{mydomain.com}. - MX
*.{mydomain.com}10 in1-smtp.messagingengine.com - MX
*.{mydomain.com}20 in2-smtp.messagingengine.com
Webmail Login Portal
- Allows you to log in to your account at
http://mail.{mydomain.com}. - CNAME
mail.{mydomain.com}mail.fastmail.com
Allow mail at subdomains
- An 'A' record hides the wildcard subdomain MX record. This overrides that to allow receiving email addressed to
foo@mail.{mydomain.com}. - MX
mail.{mydomain.com}10 in1-smtp.messagingengine.com - MX
mail.{mydomain.com}20 in2-smtp.messagingengine.com
DKIM
- Allows us 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. Note you'll need to add all three.
- CNAME
fm1._domainkey.{mydomain.com}fm1.{mydomain.com}.dkim.fmhosted.com - CNAME
fm2._domainkey.{mydomain.com}fm2.{mydomain.com}.dkim.fmhosted.com - CNAME
fm3._domainkey.{mydomain.com}fm3.{mydomain.com}.dkim.fmhosted.com - Deprecated, for old domains only:
- CNAME
mesmtp._domainkey.{mydomain.com}mesmtp.{mydomain.com}.dkim.fmhosted.com
- CNAME
SPF
- Allows receivers to know you send your mail via Fastmail, and other servers.
- TXT
{mydomain.com}v=spf1 include:spf.messagingengine.com ?all
Client email auto-discovery
- Allows email clients to automatically find the correct settings for your account.
- SRV
_submission._tcp.{mydomain.com}0 1 587 smtp.fastmail.com - SRV
_imap._tcp.{mydomain.com}0 0 0 . - SRV
_imaps._tcp.{mydomain.com}0 1 993 imap.fastmail.com - SRV
_pop3._tcp.{mydomain.com}0 0 0 . - SRV
_pop3s._tcp.{mydomain.com}10 1 995 pop.fastmail.com - SRV
_jmap._tcp.{mydomain.com}0 1 443 api.fastmail.com
Client CardDAV auto-discovery
- Allows CardDAV clients to automatically find the correct settings for your account.
- SRV
_carddav._tcp.{mydomain.com}0 0 0 . - SRV
_carddavs._tcp.{mydomain.com}0 1 443 carddav.fastmail.com
Client CalDAV auto-discovery
- Allows CalDAV clients to automatically find the correct settings for your account.
- SRV
_caldav._tcp.{mydomain.com}0 0 0 . - SRV
_caldavs._tcp.{mydomain.com}0 1 443 caldav.fastmail.com