Fastmail Release Notes

US or EU? Your choice

Many of you have been telling us that where your email is stored matters to you. There are various reasons for this, like local law, keeping your data close to home, or compliance.

You can now make the European Union the primary home for your Fastmail data, on our own secure servers in Amsterdam. Previously, all accounts were stored entirely in the US. Now you have more choice.

Built by us, not rented from someone else

We’ve installed our own servers, co-located in a secure facility in Amsterdam, set up by our own engineers. This new location is built to the same high standards as our existing infrastructure in Philadelphia and St Louis, with our own hardware and our own software — specified right down to the exact model of disks in each machine.

In all our locations, data is stored encrypted at rest inside locked racks, and managed by our in-house team. We don’t rent computing or management services from a big cloud provider and pass on their assurances. That’s how we’ve approached privacy, reliability, and performance for more than 25 years.

For many years, we have kept at least two copies of everybody’s email on separate servers in their primary location, and at least one more in a geographically separate location to ensure data safety.

Here’s the detail about where your data will flow based on your regional choice.

If your account is in the EU region: …

In brief

For National Email Day, we’re shipping something new. Fastmail now has an MCP server at https://api.fastmail.com/mcp.

MCP is an open standard, not tied to any one AI provider, for how AI clients talk to external data and tools. Think of it as another API sitting alongside IMAP, CalDAV, and CardDAV, except instead of being designed for mail apps or calendar clients, it’s designed for AI models to use directly.

So if you point your AI client (like Claude or ChatGPT) at our MCP server, you can ask it things like “what’s on my calendar tomorrow?”, “draft a reply to Sarah’s email about the Q3 budget”, or “find my dentist’s address in my contacts” and it will do them against your real Fastmail account.

The longer story — your data, your choice

To be clear about what this isn’t: we have not integrated AI into Fastmail. There’s no chatbot bolted onto the inbox, and your mail isn’t being piped through a model in the background. The MCP server is simply another API endpoint for you to use, if you want to, with the AI client of your choice. …

Today we’re releasing a major update to the Fastmail interface, with improvements focused on making mulitasking and compose better. Here’s what’s new.

Multi-window support

Sometimes you need to reference one email while replying to another, or draft several messages at once. Fastmail now supports opening compose and conversation views in separate windows.

Hold Shift when clicking reply, forward, or any compose action to open it in a new window. You can also use Shift+R to reply in a new window, or Shift+A to reply all. Or pop out a whole conversation into its own window by shift-clicking in the message list, or using the button next to the subject in the top right if it’s already open.

Your undo send timer works across windows too — if you send from a pop-out window, the undo notification appears in your main window so you’re still in control.

Inline replies

Replying to a message in a conversation now keeps you right where you are. Instead of switching to a separate compose screen, your reply appears inline within the thread, so you can see the full conversation while you write. It’s the most natural way to reply — you stay in context, and your draft lives alongside the messages you’re responding to.

If you’d rather compose in a focused view like before, you can expand your reply to full screen at any time. We’ll remember your preference.

A cleaner compose …

Fastmail is now available as a dedicated desktop app for Mac, Windows, and Linux. It’s the same Fastmail you know and love, now with the focus and convenience of a standalone app.

With our desktop app you can:

• Launch Fastmail from your dock or taskbar and find it in your platform’s app switcher.
• Make Fastmail your default email client, so email links create a new message directly in Fastmail.
• Work whenever, wherever, with full offline support, just like our mobile apps. You can always read your mail, manage your calendar, and write replies — your changes sync back seamlessly when you reconnect.

Desktop app screenshot on a Mac

Whether you’re on macOS, Windows, or your favourite Linux distribution, you’ll find the app feels right at home on your platform, with native notifications, menus, and system integrations.

Getting started is simple. Download the app for your platform, sign in with your Fastmail credentials, and you’re ready to go.

The internet is available in more places every day, from subways to aeroplanes. But it’s still not universal, and it always seems to disappear at the most inopportune time. The overwhelmed mobile network cuts out just when you need that concert ticket. You realise you don’t have the address of your hotel just after landing in a country with no roaming agreement.

Today, we’re pleased to announce full offline support for all our customers, in our apps and even on the web. No internet? No problem.

How do I turn on offline support?

We’ll be automatically enabling offline support for users of our iOS and Android apps progressively over the coming weeks. But if you can’t wait, or want offline support in your web browser, you can turn it on in Settings → Offline.

Screenshot of offline settings

Depending on the size of your account and the speed of your internet connection, it can take a few minutes or sometimes longer to do the initial sync. To allow the syncing to occur just leave the tab open in the browser (even in the background) until it shows it’s ready. Due to background processing restrictions on mobile platforms, our app can only do this initial sync while running in the foreground, but you can keep using it as normal while this is happening. …

Today we released another significant update to the Fastmail web and mobile apps, introducing more beautiful theming and faster navigation on desktop, plus a powerful new search tool to help you find the email you’re looking for.

Beautiful new themes

We’ve revised the Fastmail UI to make it more balanced, more focused, and pull in more color from your theme. Head over to the settings and you’ll find many beautiful new default themes to choose from, or make it personal with custom colors.

Faster navigation

The tab bar in our mobile app has allowed switching between your mail, calendar, and other apps in just one tap for years. Now, webmail gets quick app switching too. Just like on mobile you can choose which apps to show in the settings, or turn them all off to hide the navigation bar entirely.

For our customers with multiple accounts, it’s now much faster to move between them with our new quick user switching in the top right. Log in to more than one account in our mobile app and you’ll see the quick user switcher appear there too.

Finally, our calendar on desktop now has faster navigation between day/week/month view. Want something more unusual? Click on the selected tab again to customise the number of days/weeks on show.

Fine-tune your search

Our new search refinement toolbar lets you quickly add, remove, or change filters to narrow down your search. …

I wrote back in December about my ideas for a new skiplist based database format for the Cyrus IMAP server.

I spent a bunch of time over the next month writing just that. It’s called twom, “two” for the dual level0 pointers (the same as twoskip) and “m” for mmap and mvcc. I had planned to pronounce it “tomb” (for “it has tombstone records”) but have wound up usually saying “two em” for clarity. Maybe as this is posted on a Friday 13th we can call it “tomb” just for today.

All the code was in a merged pull request. The database itself is just a single standalone C language source file and associated header file. There’s also a cyrusdb interface wrapper, and a copy of xxHash directly in our source tree as well:

brong@elg:~/src/cyrus-imapd$ wc -l lib/*twom* lib/xxhash.h
   421 lib/cyrusdb_twom.c
  3298 lib/twom.c
   157 lib/twom.h
  7091 lib/xxhash.h
 10967 total

Amusingly, xxhash.h takes more space than anything else (and the lion’s share of the CPU usage as well, despite being much faster than crc32 as used in twoskip).

Why a new database format? …

Today we’re launching a new look for your inbox, in both our webmail and mobile apps. Familiar but refined, the message list is now cleaner and more focused. Avatars help quickly identify who’s in the conversation, and one-click hover actions let you easily archive or delete.

Make it yours with easier customisation, with live updates as you try out different options. Don’t have a Fastmail account yet? Here’s what you’re missing:

And more

We’ve also focused on fixing the niggling small things. We’ve improved support for using a mouse or pencil in our iPad app. Made it easier to quickly create a contact or event while reading a message. Added an option to stop messages from being automatically marked as read when you open them. We’ve even moved the “report phishing” action to be next to “report spam”. Finally.

On mobile you can also now choose what apps are shown in the mobile navigation bar at the bottom (or turn them all off to hide it). Missing your quick hover actions? Configure up to four custom swipe actions to fly through your mail on the go. To select a message, just press and hold, or swipe with two fingers.

We hope you enjoy the new look. Thanks to all our beta testers for the feedback they sent in. If you too want to get a sneak peek of what’s coming next at Fastmail, just log in at beta.fastmail.com. Coming soon … full offline support!