How does mail synchronization work?

This guide will explain the dual method-approach used by Tekst to keep mailboxes up-to-date. This 

Real-time webhooks (primary)

When you connect a mailbox, Tekst registers Microsoft Graph API subscriptions to monitor:

• New emails created in Inbox
• Updates to existing emails (e.g., read status, categories)
• Sent Items folder changes

Webhooks deliver notifications within 5 minutes of changes. Subscriptions auto-renew every 6 hours to maintain continuous monitoring (Microsoft Graph subscriptions expire after 3-30 days depending on resource type).

Polling fallback (backup)

If webhooks fail renewal after 3 retry attempts, Tekst automatically switches to hourly polling:

• Queries messages received since last successful sync using receivedDateTime filter
• Processes up to 400 email threads per batch
• Continues until webhooks re-establish or manual reconnection occurs

Delta sync and state management

After initial backfill, Tekst uses Microsoft Graph delta queries to fetch only changed items, storing a delta token for each mailbox to minimize API calls and improve performance.

Real-time sync reduces manual triage time by up to 200% for shared inboxes by enabling immediate AI categorization and workflow triggers.