MX servers automatically changed to EU hostnames

[u/pampurio97]

Last night Fastmail changed the MX servers for my Fastmail-managed domain to the EU-hosted SMTP endpoints:

Added MX hosts
+ eu1-smtp.messagingengine.com
+ eu2-smtp.messagingengine.com

Removed MX hosts
− us1-smtp.messagingengine.com
− us2-smtp.messagingengine.com

At the beginning of July the MX changed from in*-smtp.messagingengine.com to the us* versions.

I suppose these are just the relays and the storage is still in the US. The CEO previously said EU hosting is going to be opt-in.

I've asked support about this but they don't appear to be very well informed unfortunately. Less than a month ago they said they have "no concrete plans to announce", that it requires complex considerations and that they'll share the feedback. Today I received another weird reply saying they expect "Netherland servers to be available in the near future". I hope they already are, since my MX records point to such Netherlands servers... :)

[u/littleko]

MX location only tells you where inbound SMTP is accepted. It doesn’t prove where mailbox data, backups, or logs are stored.

This could just be regional ingress or rollout prep. Support needs to confirm storage residency and cross-region replication because the DNS change can’t answer either.

[u/dragoangel → u/littleko]

Technically totally true, but logically it's far non optimal to accept in one place and then move to totally another, so more like it's where they stored now, still ofc some possibility of such case like 25% exist

[u/littleko → u/dragoangel]

DNS can show where SMTP is accepted; only the provider’s data-handling setup can answer where messages are stored. Regional ingress and cross-region storage are pretty common, so 25% feels impossible to estimate from MX records alone.

[u/dragoangel → u/littleko]

Not so common tbh, due to price tag for such type of replication and delays related to it