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ReportsExchange ReportsMail Flow Report

Mail Flow Report

Message volume over time including sent and received counts, top senders and recipients, external vs. internal traffic, and message size distribution across your Exchange Online environment.

Overview

The Mail Flow Report provides comprehensive visibility into email traffic patterns across your organization. Track message volumes, identify top communicators, and analyze traffic patterns to optimize your mail infrastructure and detect anomalies.

Report Columns

ColumnDescription
DateThe reporting period date
Messages SentTotal outbound messages
Messages ReceivedTotal inbound messages
Internal MessagesMessages within the organization
External InboundMessages received from outside the organization
External OutboundMessages sent to outside the organization
Average SizeAverage message size in KB
Total VolumeTotal data transferred

Traffic Analysis

The report breaks down mail flow into several views:

  • Volume Over Time — Daily, weekly, or monthly message counts with trend lines
  • Top Senders — Users sending the most messages
  • Top Recipients — Users receiving the most messages
  • External Traffic — Inbound and outbound messages by external domain
  • Message Size Distribution — Breakdown of messages by size ranges

Key Metrics

  • Total messages sent/received in the selected period
  • Peak sending hours to identify busy periods
  • External to internal ratio for traffic pattern analysis
  • Average message size and large message counts

Filters

  • Date Range — Last 7 days, 30 days, 90 days, or custom
  • Direction — All, Inbound, Outbound, Internal
  • Users — All users, specific users, or groups
  • Domain — Filter by sender or recipient domain
  • Mailbox Type — User, Shared, Room, Equipment

Anomaly Detection

The report highlights unusual patterns:

  • Sudden spikes in outbound mail (possible spam or compromised account)
  • Unusual external domains receiving large volumes
  • Significant changes from baseline traffic patterns

Graph API Data Sources

  • GET /reports/getEmailActivityCounts
  • GET /reports/getEmailActivityUserDetail

API Reference

  • GET /api/reports/exchange/mail-flow — Get mail flow statistics
  • GET /api/reports/exchange/mail-flow/top-senders — Get top senders
  • GET /api/reports/exchange/mail-flow/top-recipients — Get top recipients
  • POST /api/reports/exchange/mail-flow/export — Export report data
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