MailDaemon

1.3.19

internal/functions/Send-GraphMail.ps1

function Send-GraphMail {
    <#
    .SYNOPSIS
        Sends an email via Graph API.
     
    .DESCRIPTION
        Sends an email via Graph API.
        Must be connected to Graph first using Connect-EntraService.
     
    .PARAMETER From
        Who sends the email.
        Provide the UPN to the user account, will use the default email address only.
     
    .PARAMETER To
        Recipient of the email.
     
    .PARAMETER Cc
        Additional recipients of the email.
     
    .PARAMETER Bcc
        Even more recpients of the email.
        Invisible to each other.
     
    .PARAMETER Subject
        Subject of the email to send.
        Defaults to "<no subject>"
     
    .PARAMETER Body
        Body (text) of the email.
     
    .PARAMETER BodyAsHtml
        Whether the email is to be sent as html body.
        Will be sent as a plaintext email if not specified.
     
    .PARAMETER Attachments
        Any files to include in the email.
     
    .PARAMETER Priority
        The priority to assign to the email
     
    .EXAMPLE
        PS C:\> Send-GraphMail -From fred@contoso.com -To Max@contoso.com -Subject Test -Body "Test Mail"
 
        Sends a simple test email.
    #>
    [CmdletBinding()]
    param (
        [string]
        $From,

        [string[]]
        $To,

        [string[]]
        $Cc,

        [string[]]
        $Bcc,
        
        [string]
        $Subject = '<no subject>',

        [string]
        $Body,
        
        [switch]
        $BodyAsHtml,

        [string[]]
        $Attachments,

        [ValidateSet('Low', 'Normal', 'High')]
        [string]
        $Priority
    )

    Assert-EntraConnection -Service Graph -Cmdlet $PSCmdlet

    $draft = $null

    try{
        # Step 1: Create Draft
        $reqBody = @{
            subject = $Subject
        }
        if ($Body) {
            $reqBody["body"] = @{
                contentType = 'text'
                content = $Body
            }
            if ($BodyAsHtml) { $reqBody.body.contentType = 'html' }
        }
        if ($To) {
            $reqBody['toRecipients'] = @()
            foreach ($entry in $To) {
                $reqBody['toRecipients'] += @{ emailAddress = @{ address = $entry } }
            }
        }
        if ($Cc) {
            $reqBody['ccRecipients'] = @()
            foreach ($entry in $Cc) {
                $reqBody['ccRecipients'] += @{ emailAddress = @{ address = $entry } }
            }
        }
        if ($Bcc) {
            $reqBody['bccRecipients'] = @()
            foreach ($entry in $Bcc) {
                $reqBody['bccRecipients'] += @{ emailAddress = @{ address = $entry } }
            }
        }
        if ($Priority) {
            $reqBody['importance'] = $Priority.ToLower()
        }

        $draft = Invoke-EntraRequest -Method Post -Path "users/$From/messages" -Header @{
            'Content-Type' = 'application/json'
        } -Body $reqBody

        # Step 2: Upload Attachments
        foreach ($attachment in $Attachments) {
            Publish-GraphAttachment -Path $attachment -Message "users/$From/messages/$($draft.id)"
        }

        # Step 3: Send
        $null = Invoke-EntraRequest -Method POST -Path "users/$From/messages/$($draft.id)/send"
    }
    catch {
        # Step X: Undo on failure
        if ($draft) {
            Invoke-EntraRequest -Method DELETE -Path "users/$From/messages/$($draft.id)"
        }
        throw
    }
}