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_on_Fire's avatar
_on_Fire
Copper Contributor
Mar 27, 2025

High Volume Email accounts and sign-in logs

When looking at the Entra ID sign-in logs for a High Volume Email account I noticed that it seems that after the first succesful login from a certain public IP subsequent logins are no longer logged that day (or at least a number of hours after).

This makes it cumbersome to test how Conditional Access affect the login via the sign-in logs.

Has anyone else experienced this?

3 Replies

  • _on_Fire's avatar
    _on_Fire
    Copper Contributor

    GageSterlingThank you, but I'm not looking for the login history from Exchange Online. I'm looking for more recent entries in the Entra ID Sign-in logs of the HVE account after the first successful login of the day.

  • GageSterling's avatar
    GageSterling
    Iron Contributor

    1. Quickly get the login log (PowerShell command)
    powershell
    # Get the last 100 login logs for a given mailbox (adjust the number as needed)
    Get-MailboxStatistics -Identity “email address removed for privacy reasons” | Get-MailboxLoginStatistics -ResultSize 100
    2.# Filter abnormal logins (e.g. non-company IP segments)
    $startDate = (Get-Date).AddDays(-7)
    Get-MailboxLoginStatistics -Identity “email address removed for privacy reasons” | 
        Where { $_.ClientIPAddress -notlike “192.168.*” -and $_.LoginTime -gt $startDate }
    3. Automated monitoring scripts (run daily)
    powershell
    # Save to log file
    $logPath = “C:\Logs\MailboxLoginAudit_$(Get-Date -Format yyyyMMdd).csv”
    Get-Mailbox -ResultSize Unlimited | 
        Where { $_.MessageCount -gt 10000 } | 
        Get-MailboxLoginStatistics | 
        Export-Csv $logPath -NoTypeInformation
    4. Key configuration adjustments
     Extend log retention time:
    powershell
    # Set audit log retention to 90 days (default 30 days)
    Set-AdminAuditLogConfig -AuditLogAgeLimit 90
    4. Enable enhanced logging:
    powershell
    Set-Mailbox -Identity “email address removed for privacy reasons” -AuditEnabled $true -AuditLogAgeLimit 180
    5. Real-time alert settings
    powershell
    # Create an abnormal login alert rule
    New-TransportRule -Name “SuspiciousLoginAlert” `
        -AnyOfRecipientAddressContains “email address removed for privacy reasons” `
        -ExceptIfClientIPAddressesMatch “192.168.0.0/16” `
        -NotifySender “SecurityAlert”
    Emergency handling
    5. Lock the suspicious account immediately:
    powershell
    Set-Mailbox -Identity “email address removed for privacy reasons” -AccountDisabled $true
    6. Quickly export evidence:
    powershell
    Get-MailboxLoginStatistics -Identity “email address removed for privacy reasons” -ResultSize Unlimited |
        Select LoginTime,ClientIPAddress,ApplicationId |
        Export-Csv “C:\Investigation\LoginRecords.csv” -NoTypeInformation
    7. Best Practices
    Archive commands on a regular basis (run monthly)
    powershell
    # Archive last month's logs to a dedicated mailbox
    $archiveMB = “email address removed for privacy reasons”
    Search-Mailbox -Identity $archiveMB -SearchQuery “kind:email” -TargetMailbox $archiveMB -TargetFolder “Logs_$(Get-Date -Format yyyyMM)” -DeleteContent

    • Ahmed_Masoud97's avatar
      Ahmed_Masoud97
      Steel Contributor

      Have you tried to Modify the Conditional Access policy briefly (e.g., require MFA), which forces re-evaluation and logging?  

      Best,  

      Ahmed Masoud  

      Best,  

      Ahmed Masoud  

      LinkedIn

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