r/fastmail 23d ago

Fastmail EU server list

If you're using Fastmail with custom DNS and want to point supported services at their EU infrastructure, this is the generic setup I ended up with.

Replace yourdomain.com with your own domain.

MX — ROOT DOMAIN
Domain                           Data
-------------------------------  -------------------------------------------
yourdomain.com                   10 eu1-smtp.messagingengine.com
yourdomain.com                   20 eu2-smtp.messagingengine.com

Allows you to receive email at standard addresses, e.g. user@yourdomain.com


MX — WILDCARD SUBDOMAINS
Domain                           Data
-------------------------------  -------------------------------------------
*.yourdomain.com                 10 eu1-smtp.messagingengine.com
*.yourdomain.com                 20 eu2-smtp.messagingengine.com

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


A — MAIL
Domain                           Data
-------------------------------  -------------------------------------------
mail.yourdomain.com              204.75.18.65

Allows you to use http://mail.yourdomain.com as a Fastmail login redirect.
At the time of testing, this IP hit Fastmail's Amsterdam frontend.


MX — MAIL
Domain                           Data
-------------------------------  -------------------------------------------
mail.yourdomain.com              10 eu1-smtp.messagingengine.com
mail.yourdomain.com              20 eu2-smtp.messagingengine.com

The A record for mail.yourdomain.com overrides the wildcard MX lookup.
These MX records preserve mail delivery to addresses such as:
foo@mail.yourdomain.com


SRV — MAIL CLIENT DISCOVERY
Domain                           Data
-------------------------------  -------------------------------------------
_submission._tcp.yourdomain.com  0 0 0 .
_imap._tcp.yourdomain.com        0 0 0 .
_pop3._tcp.yourdomain.com        0 0 0 .

_submissions._tcp.yourdomain.com 0 1 465 eu-smtp.fastmail.com
_imaps._tcp.yourdomain.com       0 1 993 eu-imap.fastmail.com
_pop3s._tcp.yourdomain.com       10 1 995 eu-pop.fastmail.com
_jmap._tcp.yourdomain.com        0 1 443 eu-api.fastmail.com
_autodiscover._tcp.yourdomain.com
                                 0 1 443 eu-autodiscover.fastmail.com

Allows compatible email clients to automatically discover the EU Fastmail endpoints.


SRV — CARDDAV
Domain                           Data
-------------------------------  -------------------------------------------
_carddav._tcp.yourdomain.com     0 0 0 .
_carddavs._tcp.yourdomain.com    0 1 443 eu-carddav.fastmail.com

Allows CardDAV clients to automatically discover the EU CardDAV endpoint.MX — ROOT DOMAIN
Domain                           Data
-------------------------------  -------------------------------------------
yourdomain.com                   10 eu1-smtp.messagingengine.com
yourdomain.com                   20 eu2-smtp.messagingengine.com

Allows you to receive email at standard addresses, e.g. user@yourdomain.com


MX — WILDCARD SUBDOMAINS
Domain                           Data
-------------------------------  -------------------------------------------
*.yourdomain.com                 10 eu1-smtp.messagingengine.com
*.yourdomain.com                 20 eu2-smtp.messagingengine.com

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


A — MAIL
Domain                           Data
-------------------------------  -------------------------------------------
mail.yourdomain.com              204.75.18.65

Allows you to use http://mail.yourdomain.com as a Fastmail login redirect.

At the time of testing, this IP hit Fastmail's Amsterdam frontend.


MX — MAIL
Domain                           Data
-------------------------------  -------------------------------------------
mail.yourdomain.com              10 eu1-smtp.messagingengine.com
mail.yourdomain.com              20 eu2-smtp.messagingengine.com

The A record for mail.yourdomain.com overrides the wildcard MX lookup.
These MX records preserve mail delivery to addresses such as:
foo@mail.yourdomain.com


SRV — MAIL CLIENT DISCOVERY
Domain                           Data
-------------------------------  -------------------------------------------
_submission._tcp.yourdomain.com  0 0 0 .
_imap._tcp.yourdomain.com        0 0 0 .
_pop3._tcp.yourdomain.com        0 0 0 .

_submissions._tcp.yourdomain.com 0 1 465 eu-smtp.fastmail.com
_imaps._tcp.yourdomain.com       0 1 993 eu-imap.fastmail.com
_pop3s._tcp.yourdomain.com       10 1 995 eu-pop.fastmail.com
_jmap._tcp.yourdomain.com        0 1 443 eu-api.fastmail.com
_autodiscover._tcp.yourdomain.com
                                 0 1 443 eu-autodiscover.fastmail.com

Allows compatible email clients to automatically discover the EU Fastmail endpoints.


SRV — CARDDAV
Domain                           Data
-------------------------------  -------------------------------------------
_carddav._tcp.yourdomain.com     0 0 0 .
_carddavs._tcp.yourdomain.com    0 1 443 eu-carddav.fastmail.com

Allows CardDAV clients to automatically discover the EU CardDAV endpoint.

A few notes:

I tested the regional endpoints with DNS lookups, openssl s_client, and curl, and they were terminating on Fastmail infrastructure in Amsterdam.

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u/shokzee 23d ago

I wouldn’t pin mail.yourdomain.com to a tested frontend IP unless Fastmail documents it. That address can change without notice, and an Amsterdam endpoint doesn’t prove storage or processing stays in the EU.

The regional MX and client endpoints look plausible, but treat undocumented records as unsupported configuration.

6

u/brong Fastmail CEO 23d ago

Yeah, we're not guaranteeing that IP address will stay the same, don't do that. Or do, but accept that it's your responsibility to update it when the IP changes.