How to Use Fastmail Calendar with Google, Outlook, and iCloud

Fastmail already offers connections with Google and iCloud, so you may be able to manage those calendars from Fastmail without another service.

Choose the setup for the job you need: editing Google appointments inside Fastmail, displaying Fastmail on a phone, or putting Fastmail busy time into an Outlook work account.

Connect another calendar inside Fastmail

Fastmail's built-in external-calendar feature supports connections with Google and iCloud. Open Settings → Calendars, find Add account, choose the external service, and follow its sign-in flow.

Fastmail says connected calendars can be managed from its interface while remaining updated at the source service. It also offers manual CalDAV connections. Its calendar synchronization guide covers those options and account-specific details.

This may be the right solution when Fastmail is where you want to plan your day. Check which calendar is selected before saving a new appointment: creating an event in a Fastmail-owned calendar is different from creating it in the Google calendar displayed next to it.

For externally connected calendars, the original account, such as Google, usually still handles invitations and replies. Accept the invitation into the account it was sent to.

Add Fastmail to a calendar app

Fastmail supports CalDAV for calendar clients. Its documented server is https://caldav.fastmail.com/, using your full Fastmail email address and an app-specific password. Your normal Fastmail password will not work here. Fastmail keeps the current values on its server names page.

On an iPhone or Mac, a native CalDAV account can provide viewing and editing without copying appointments between providers. Add a CalDAV account on iPhone or Mac directly. On Android, use a CalDAV sync adapter alongside a calendar app.

Classic Outlook for Windows can use a compatible desktop CalDAV add-in. Check the actual Outlook version first: new Outlook and browser Outlook do not use classic desktop add-ins in the same way. A published feed is another option for viewing, but it remains read-only and refreshes on the subscriber's schedule.

For somebody who only wants a complete personal view, one good app holding both accounts is often enough.

When another account needs your availability

Imagine a dentist appointment in Fastmail while coworkers check your Microsoft 365 availability. Displaying both accounts on your phone does not add a busy block to the Microsoft 365 calendar they check.

A manual Busy event on the work calendar is a reasonable answer for occasional commitments. Use a neutral title and remember to update it if the appointment moves.

For frequent changes, Avum supports CalDAV alongside Google, Microsoft, and iCloud. Connect Fastmail using its documented details, connect the destination account, and create a Sync Rule from the relevant source calendar. Limit the copied information to what that destination needs.

Confirm that the destination permits writes and start with one direction, especially if Fastmail already maintains another connection for the same schedule.

Move a test appointment at the source and inspect the destination. For work availability, open the booking page or ask a colleague to inspect free/busy. Include recurring events and cancellations in the sync checks.

Watch for multiple reminders

An event copied into more than one account can produce an alert from each account. Fastmail documents several causes of duplicate reminders and invitation copies in its troubleshooting guide.

Keep the reminders you rely on in Fastmail or your chosen primary app. Turn off extra alerts on copies that only communicate availability, then confirm that the wanted reminder still arrives. Leave the original appointment in place.

Ready to try controlled copies from Fastmail? Start your free 30-day trial with Avum today.