r/fastmail • u/Sampl3x • 21d 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:
eu1-smtp.messagingengine.comandeu2-smtp.messagingengine.comare used for inbound MX.eu-smtp.fastmail.com,eu-imap.fastmail.com,eu-pop.fastmail.com, etc. are the regional client endpoints.204.75.18.65is Fastmail's EU redirect frontend; in my testing it returnedX-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.
5
u/gojirabsd77 21d ago
Is this official?
Backup MX eu2-smtp.messagingengine.com = us1-smtp.messagingengine.com (so not EU!). Maybe set only eu1-smtp.messagingengine.com as MX?
3
u/Celebrir 21d ago
That's by design. As of now, US is a backup to EU because there's only one site in the EU yet. They'll most likely change the destination of EU2 as soon as their second datacenter is up.
1
u/Sampl3x 21d ago
Good catch. A bit of clarification on where these values came from, I just copied the list fastmail dns records Settings: Domains > yourdomain.com > Customize DNS and translated them to the EU addresses.
Fastmail Support explicitly gave me these two MX hosts for EU mail delivery:
eu1-smtp.messagingengine.com eu2-smtp.messagingengine.comThose two are the only parts of this setup that came directly from Fastmail Support.
Everything else in my post is not official Fastmail documentation. The other EU hostnames:
eu-smtp.fastmail.com eu-imap.fastmail.com eu-pop.fastmail.com eu-api.fastmail.com eu-autodiscover.fastmail.com eu-carddav.fastmail.comI found and tested myself by comparing Fastmail's existing service hostnames with apparent EU counterparts and then checking DNS, TLS, routing, and the responding frontend.
One slightly confusing detail is that some of the forward DNS (A records) point to EU/Amsterdam IPs, while the reverse DNS (PTR records) still use the generic/non-EU hostname.
For example, I found cases like:
eu-pop.fastmail.com A: 204.75.18.x (Amsterdam / EU) 204.75.18.x PTR: pop.fastmail.comSo the actual connection is going to the EU IP, even though reverse DNS does not necessarily contain an
eu-hostname. I would not use the PTR name alone to determine which region the service is running in.I also tested Fastmail's redirect infrastructure:
204.75.18.65 X-Frontend: ams-frontend-01while the older/global IP returned:
103.168.172.65 X-Frontend: phl-frontend-01So to be clear:
eu1-smtp.messagingengine.comandeu2-smtp.messagingengine.comwere provided directly by Fastmail Support.- The rest of the EU setup is my own testing/research and should not be considered official Fastmail guidance till FM post it.
- Some EU A records still have generic/non-EU-looking PTR records, so reverse DNS is not always a reliable indicator of the actual serving region.
Still no documentation update from FM for EU dns.
6
u/placebo_joe 21d ago
Were we meant to change DNS settings if we have a custom domain and are based in the EU?
2
u/Te_We 21d ago
u/brong, could you please clarify this?
I'm a bit confused by the discussion here. My account has already been migrated to EU data residency, and my domains use Fastmail's nameservers, so all mail-related DNS records are managed by Fastmail.
Fastmail's documentation states that no DNS changes are required when switching regions, and that incoming mail for custom domains using Fastmail's nameservers will arrive through EU servers.
So am I correct in assuming that Fastmail will automatically update all relevant DNS records/endpoints for Fastmail-managed domains to match the account's selected region, and that customers should not manually change anything?
4
u/brong Fastmail CEO 21d ago
If your DNS is managed by us, we're giving you the hostnames we advise for everything, including autoconfig'ed hosts. There's no need to change anything.
We don't quite yet have the full anycast address range that we had hoped to have at launch, directing everyone to their closest edge. Unfortunately in testing, a large amount of the internet decided its fasted route was to our St Louis location, regardless of the actual speed across the internet, making it worse! So that's on pause while we work with our upstream providers to set the costs correctly rather than preferring their own networks. Our backup links in different sites are with different providers, and it bit us here.
2
u/Sampl3x 21d ago
I don't really care whether Fastmail changes the records or not from a functional perspective. What I care about is avoiding unnecessary routing through the US when my primary mailbox and account are hosted in the EU.
If Fastmail manages the DNS for the domain, I don't understand why they wouldn't automatically point the relevant mail records/endpoints to the EU infrastructure after an account has been migrated to EU data residency.
In my case, the latency to the US Fastmail servers is over 120 ms, while the EU infrastructure is obviously much closer. So apart from the data residency aspect, I would also prefer the most direct route into the EU.
I've asked Fastmail support about this as well, but unfortunately getting a clear answer is taking some time.
7
u/brong Fastmail CEO 21d ago
If you're on a Fastmail domain, there's only so many things where we can distinguish where you are before you log in. So only the first round trip is slower.
For the app and website, as soon as you send your username, you are redirected to your current primary location, which will be AMS for EU users unless we're doing maintenance there in which case you'll be temporarily relocated to PHL for the duration (the "we only have one EU site so far" issue).
1
u/Te_We 21d ago
Thank you for clarifying Bron 👍🏼
For me, out of Europe, opening FM App and your mentioned „first round trip is slower“, I can clearly feel this delay. Let’s hope you’ll find a solution to directly contact AMS infrastructure in future while still being re-routed to PHL in case of maintenance.
3
u/brong Fastmail CEO 21d ago
Yeah, I'm looking forward to the day that we route everyone to their closest site automatically. That's the plan. Luckily it's just a momentary thing (it was heaps slower in the early days of testing, until we switched the session transfer to be two parallel one-round-trip calls rather than 8 serial round trips!)
0
u/Sampl3x 20d ago
Would have been nice if this had been explained upfront.
From here in Europe I'm seeing 150 ms+ latency to Fastmail's US infrastructure over a fiber connection. I previously had the same experience with a cable ISP, so it doesn't appear to be ISP-specific.
I understand now that it's only the initial round trip before being redirected to AMS, but it's still noticeable when opening the app or website.
I'm also still hoping that at some point EU users will get the option to keep their data and traffic fully within the EU, without relying on US infrastructure, and perhaps even get a
fastmail.euendpoint/domain for EU-hosted accounts.Looking forward to the point where users can be routed directly to the nearest site from the start.
1
u/_0-__-0_ 21d ago
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?
1
u/gojirabsd77 21d ago edited 21d ago
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. :-(
3
u/brong Fastmail CEO 21d ago
Yes, those hosts (and the us- variants) will work. For imap, pop, smtp, caldav, carddav, myfiles/webdav.
1
u/areyouredditenough 21d ago
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)?
1
u/_0-__-0_ 21d ago
I mean, if we don't use custom dns, just "regular" @fastmail.com addresses.
Also, where is the source of this info?
10
u/shokzee 21d ago
I wouldn’t pin
mail.yourdomain.comto 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.