Manual DNS configuration

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 information or instructions for setting up your domain in your Fastmail account? Please see our Custom domains with Fastmail help page.

Looking for general background information on how DNS works? Please see our General DNS info help page.

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.

All entries have a 1 hour TTL.

Websites

Allows you to host websites at http://{mydomain.com} from your Fastmail file storage.

Type Host Value
CNAME www.{mydomain.com} web.fastmail.com

 

Standard Mail

Allows you to receive email at standard addresses, e.g. user@{mydomain.com}.

Type Host Value Priority
MX @ in1-smtp.messagingengine.com 10
MX @ in2-smtp.messagingengine.com 20

 

Subdomain Websites

Allows you to host websites at subdomains, including http://www.{mydomain.com}, from your Fastmail file storage.

Type Host Value
CNAME *.{mydomain.com} web.fastmail.com

 

Subdomain Mail

Allows you to receive email at subdomain addresses, e.g. foo@user.{mydomain.com}.

Type Host Value Priority
MX *.{mydomain.com} in1-smtp.messagingengine.com 10
MX *.{mydomain.com} in2-smtp.messagingengine.com 20

 

Webmail Login Portal

Allows you to log in to your account at http://mail.{mydomain.com}.

Type Host Value
CNAME mail.{mydomain.com} mail.fastmail.com

 

Allow mail at subdomains

An A record hides the wildcard subdomain MX record. Setting up the below MX records overrides this to allow receiving email addressed to foo@mail.{mydomain.com}.

Type Host Value Priority
MX mail.{mydomain.com} in1-smtp.messagingengine.com 10
MX mail.{mydomain.com} in2-smtp.messagingengine.com 20

 

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 records.

Type Host Value
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 (only in use by domains that have been hosted at Fastmail before 2018):

Type Host Value
CNAME mesmtp._domainkey.{mydomain.com} mesmtp.{mydomain.com}.dkim.fmhosted.com

 

SPF

Allows receivers to know you send your mail via Fastmail, and other servers.

Type Host Value
TXT {mydomain.com} v=spf1 include:spf.messagingengine.com ?all

 

DMARC

Specifies what to do with messages that fail DKIM and SPF.

Type Host Value
TXT _dmarc.{mydomain.com} v=DMARC1; p=none;

 

Client email auto-discovery

Allows email clients to automatically find the correct settings for your account.

Type Host Priority Weight Port Target
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.

Type Host Priority Weight Port Target
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.

Type Host Priority Weight Port Target
SRV _caldav._tcp.{mydomain.com} 0 0 0 .
SRV _caldavs._tcp.{mydomain.com} 0 1 443 caldav.fastmail.com
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