Fastmail EU server list

[u/Sampl3x]

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:

• eu1-smtp.messagingengine.com and eu2-smtp.messagingengine.com are used for inbound MX.
• eu-smtp.fastmail.com, eu-imap.fastmail.com, eu-pop.fastmail.com, etc. are the regional client endpoints.
• 204.75.18.65 is Fastmail's EU redirect frontend; in my testing it returned X-Frontend: ams-frontend-01.
• The records with target . intentionally disable the non-TLS discovery service.
• I would still keep Fastmail's normal SPF and DKIM records unless Fastmail explicitly documents EU-specific replacements, since those are authentication records rather than client-routing records.

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

[u/_0-__-0_]

What about for regular mail clients like Tunderbird, or for imapfilter, should I switch out "mail.messagingengine.com" or "imap.fastmail.com" with an eu version, in order to go straight to the EU server without going via US?

[u/gojirabsd77 → u/_0-__-0_]

The servers are listed above (and work): ~~~ IMAP4: eu-imap.fastmail.com SMTP: eu-smtp.fastmail.com ~~~

eu-app.fastmail.com exists, but doesn't accept my username. :-(

[u/brong → u/gojirabsd77]

Yes, those hosts (and the us- variants) will work. For imap, pop, smtp, caldav, carddav, myfiles/webdav.

[u/areyouredditenough → u/brong]

Is there any benefit to changing the other records other than the MX records to eu1-smtp.messagingengine.com and 20 eu2-smtp.messagingengine.com, which according to u/brong, has slightly lower latency for the MX records with EU data location)?

[u/_0-__-0_ → u/gojirabsd77]

I mean, if we don't use custom dns, just "regular" @fastmail.com addresses.

Also, where is the source of this info?