Send a delayed message

Summary

This script shows how to send a delayed message with the Microsoft Graph PowerShell SDK.

The mail API in the Microsoft Graph doesn't expose any properties to defer sending a message.

Set deferred send time

Fortunately, the Graph API provides the extended properties REST API if you need to access custom data for Outlook MAPI properties that are not already exposed in the Microsoft Graph API.

Outlook MAPI provides the canonical property PidTagDeferredSendTime.

PidTagDeferredSendTime indicates a time when a client would like to defer sending a message.

Property	Value
Associated properties	PR_DEFERRED_SEND_TIME
Identifier	0x3FEF
Data type	PT_SYSTIME

When sending a message, provide a singleValueLegacyExtendedProperty object in the singleValueExtendedProperties collection property of the message resource instance.

singleValueLegacyExtendedProperty has properties id and value.

id must follow the format "{graph_type} {proptag}".

graph_type for MAPI data type PT_SYSTIME is SystemTime, and proptag is 0x03FEF.

The date and time value must be in ISO 8601 format.

• Microsoft Graph PowerShell

The script shows how to defer message delivery by specific minutes.

Input parameters:

• $SenderId: Sender id, mail or a UPN
• $RecipientEmail: The recipient of the message
• $DeliveryDelayMinutes: Delivery delay in minutes
• $Subject: The subject of the message
• $Body: The body of the message

[cmdletbinding()]
param(
    [parameter(Mandatory)]
    [string] $SenderId,
    [parameter(Mandatory)]
    [string] $RecipientEmail,
    [parameter(Mandatory)]
    [int] $DeliveryDelayMinutes,
    [parameter(Mandatory)]
    [string] $Subject,
    [parameter(Mandatory)]
    [string] $Body
)

function Send-MgUserDelayedMail {
    try {

    Connect-MgGraph -Scopes "Mail.Send"

    Import-Module Microsoft.Graph.Users.Actions

    $DeliveryTime=(Get-Date).AddMinutes($DeliveryDelayMinutes).ToUniversalTime().ToString("o")

    $Params = @{
        message = @{
            subject = $Subject
            body = @{
                contentType = "HTML"
                content = $Body
            }
            toRecipients = @(
                @{
                    emailAddress = @{
                        address = $RecipientEmail
                    }
                }
            )
            singleValueExtendedProperties = @(
                @{
                    id = "SystemTime 0x3FEF"
                    value = $DeliveryTime
                }
            )
        }
    }


    Send-MgUserMail -UserId $SenderId -BodyParameter $Params
    Write-Host "The email will be delivered at $DeliveryTime"
    }
    catch {
        Write-Host 'Failed to send delayed message'
        Write-Host $_
    }
    finally {
        Disconnect-MgGraph
    }
}

Send-MgUserDelayedMail

Check out the Microsoft Graph PowerShell SDK to learn more at: https://learn.microsoft.com/graph/powershell/get-started

Contributors

Author(s)
Martin Macháček

Disclaimer

THESE SAMPLES ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.