Mailbox Size Trend

Historical mailbox growth over 30, 60, and 90 days. Helps forecast storage needs and identify users with abnormal data accumulation patterns.

Overview

The Mailbox Size Trend report tracks how mailbox storage consumption changes over time across your Exchange Online environment. Use this report to forecast capacity needs, identify users with unusual growth patterns, and plan storage management strategies.

Report Columns

Trend Analysis

The report provides visual trend lines and analytics for:

• Organization-wide growth — Total storage consumption over time
• Per-user growth — Individual mailbox growth patterns
• Mailbox type comparison — User vs. Shared vs. Room mailbox trends
• Top growers — Users with the fastest growth rates

Alerts and Thresholds

Configure alerts for mailbox growth anomalies:

• Approaching Quota — Mailboxes above 80% of their quota
• Rapid Growth — Mailboxes growing faster than 2 GB per month
• Unusual Spike — Sudden increase in mailbox size (potential data hoarding or mailbox migration)

Filters

• Date Range — 30, 60, 90 days, or custom range
• Mailbox Type — User, Shared, Room, Equipment
• Quota Status — All, Near quota (80%+), Critical (95%+)
• Growth Rate — All, High growth, Normal, Declining
• Tenant — Filter by managed tenant

Storage Optimization Tips

1. Implement retention policies to automatically archive or delete old messages
2. Enable Online Archive mailboxes for users with large mailboxes
3. Review and clean up mailboxes with rapid growth
4. Set mailbox size quotas appropriate to user roles

API Reference

• GET /api/reports/exchange/mailbox-size-trend — Get mailbox size trend data
• GET /api/reports/exchange/mailbox-size-trend/forecast — Get growth forecast
• POST /api/reports/exchange/mailbox-size-trend/export — Export report data