Sync with Fastmail

Fastmail is a popular privacy-focused email provider with full CalDAV support, which makes it a solid host for your 2Do tasks. 2Do connects to it through the Custom CalDAV account type.

Fastmail sync carries the same things as any Custom CalDAV server: all core task fields, multiple alarms, one picture and one audio note per task, and two-way project and sub-task hierarchy. 2Do-only grouping (Smart Lists, tag groups, list groups) stays on this Mac; see What CalDAV Sync Carries.

App Password Requirement

Fastmail does not accept your regular account password from third-party apps. You need an app password created for CalDAV access (Fastmail explains these in its App passwords help article):

1. Sign in at fastmail.com and open Settings > Privacy & Security > Integrations (App passwords).
2. Click New app password.
3. Give it a name you'll recognize (2Do), and choose an access scope that includes Calendars (CalDAV).
4. Fastmail shows the password once. Copy it and keep it somewhere safe; you'll paste it into 2Do next.

Deleting the app password later revokes 2Do's access without changing your main account password.

Setup

1. Open 2Do > Settings > Sync and select the Setup tab.
2. From the Account Type pop-up, choose Custom CalDAV.
3. Fill in the connection fields:
   • Server Address — caldav.fastmail.com
   • Path — /dav/ (check Fastmail's help pages if your account documents a different path)
   • Port and Use SSL — leave at the defaults, with SSL on.
4. Enter your Username (your full Fastmail email address) and the app password you generated.
5. Click Connect. 2Do discovers your task collections on the server.
6. Repeat on each device with the same address and credentials.

Your first sync

Close Settings and press ⌘S (or click the Sync toolbar button) to run the first sync. When both sides already hold data, 2Do asks how to combine them; see Merge vs Replace before choosing.

Daily Sync

Fastmail syncs continuously while 2Do is running. Press ⌘S to force an immediate sync.

Troubleshooting

Login or password rejected

Almost always the password type: make sure the password you entered is an actual app password created in your Fastmail account, with CalDAV access, and not your regular account password. Fastmail walks you through creating one in its App passwords help article. If a previously working password stops, it may have been revoked; generate a new one at Fastmail > Settings > Privacy & Security and re-enter it in 2Do.

Connection succeeds but no task lists appear

Check that the app password's scope includes Calendars (CalDAV). A mail-only scope authenticates but exposes no calendar collections.

Adding another device

Install 2Do, choose Custom CalDAV with the exact same server address and credentials, and let the first sync pull your data down. See Setting up a new device.

Tips

tip

App passwords can be reused across your devices, so one 2Do app password covers your Mac, iPhone, and iPad. Prefer separate ones per device if you want to be able to revoke them individually.

tip

If you rely on Smart Lists, tag groups, and attachments syncing in full, Dropbox carries everything; Fastmail is the better fit when you want your tasks on a CalDAV server you already trust with your mail.