Microsoft 365

Connect your Microsoft account to sync Outlook Mail, Calendar, and Contacts with Meridian

Meridian connects to your Microsoft 365 account to sync your email, calendar, and contacts using the Microsoft Graph API.

What Syncs

• Outlook Mail – Emails, folders, and full conversation threads
• Outlook Calendar – Events across all of your calendars, including shared calendars
• Outlook Contacts – Your full contact list and contact groups

Setup

1. In Meridian, go to Settings > Connections.
2. Click Add Connection and select Microsoft.
3. Sign in with your Microsoft account in the browser window that appears.
4. Review the requested permissions and click Authorize to grant Meridian access.

Your account will appear in the Connections list once authorization is complete. Initial sync begins immediately.

Permissions

Meridian requests access to Mail, Calendar, and Contacts via the Microsoft Graph API. OAuth tokens are encrypted and stored securely on your device. Meridian does not access any other Microsoft 365 services such as OneDrive, Teams, or SharePoint.

Sync Behavior

Sync is two-way. Changes you make in Meridian are pushed back to Microsoft, and changes from Outlook appear in Meridian automatically. Meridian uses Microsoft’s delta queries for efficient incremental updates, meaning only items that have changed since the last sync are transferred.

Multiple Accounts

You can connect multiple Microsoft 365 accounts. Each appears as a separate connection with its own channels and sync state. This works with both personal Microsoft accounts and organizational (work/school) accounts.

Troubleshooting

• Token expiration – Microsoft OAuth tokens can expire or be revoked by an administrator. If sync stops working, go to Settings > Connections, find your Microsoft connection, and click Re-authorize to sign in again.
• Organizational policies – Some organizations restrict which third-party apps can access Microsoft 365 data. If you cannot authorize Meridian, contact your IT administrator to allow the Meridian application.
• Sync delays – Check your sync interval in Settings > Sync. Delta queries are efficient, so shorter intervals have minimal performance impact.
• Missing folders or calendars – Ensure the folders and calendars you want are not hidden in Outlook’s settings.