DumpDelegatesandForwardingRules.ps1

#Let's get us an admin cred!
$userCredential = Get-Credential

#Connecting to Exchange Online
$ExoSession = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $userCredential -Authentication Basic -AllowRedirection
Import-PSSession $ExoSession -DisableNameChecking | Out-Null

$allUsers = @()
$AllUsers = Get-Mailbox -ResultSize Unlimited

$UserInboxRules = @()
$UserDelegates = @()

foreach ($User in $allUsers)
{
    Write-Host "Checking inbox rules and delegates for user: " $User.UserPrincipalName;
    $UserInboxRules += Get-InboxRule -Mailbox $User.UserPrincipalname | Select-Object @{Name='Mailbox';Expression={$user.UserPrincipalName}},Name, Description, Enabled, Priority, ForwardTo, ForwardAsAttachmentTo, RedirectTo, DeleteMessage | Where-Object {($_.ForwardTo -ne $null) -or ($_.ForwardAsAttachmentTo -ne $null) -or ($_.RedirectTo -ne $null)}
    $UserDelegates += Get-MailboxPermission -Identity $User.UserPrincipalName | Where-Object {($_.IsInherited -ne "True") -and ($_.User -notlike "*SELF*")} 
}

$SMTPForwarding = $allUsers | Select-Object DisplayName,UserPrincipalName,ForwardingAddress,ForwardingSMTPAddress,DeliverToMailboxandForward | Where-Object {($_.ForwardingSMTPAddress -ne $null) -or ($_.ForwardingAddress -ne $null)}

$UserInboxRules | Export-Csv MailForwardingRulesToExternalDomains.csv
$UserDelegates | Export-Csv MailboxDelegatePermissions.csv
$SMTPForwarding | Export-Csv Mailboxsmtpforwarding.csv