• Server that is always online
• Set of logon credentials for that server
• Set of EXO credentials that can run our script (Recommend different from your main admin account)
• Scripts listed below

Implementation time:

Directions:

Prepare the needed inputs:

1. Log into a server
2. Create a directory to store the scripts and output ( C:\Scripts )
3. Copy and save off the three scripts below into your path
4. Connect to Exchange Online PowerShell
5. Get the recipients we want to get a report on Get-Mailbox -resultsize 100| select-object -property PrimarySMTPAddress | export-csv c:\scripts\recipients.csv
6. Run the New-StoredCredential.ps1 script
   1. Start Powershell
   2. Change to your directory
   3. Run .\New-StoredCredential.ps1 -Path c:\scripts\O365Account.txt -Password "<your password>"

Create the scheduled task:

1. Start Task Scheduler
2. Create a new Basic Task
3. Name it
4. Schedule it for One Time (I usually do 10 min in the past)
5. Choose to have it start a program
6. Put powershell.exe as the program to run
7. The arguments should be -noprofile -file c:\scripts\Start-AutomatedBasicScript.ps1
8. Make sure to choose "Open the properties dialog for this task when I click Finish" then finish creating the task
9. On the properties page we want to change two options
   1. Select "Run whether user is logged on or not"
   2. Select "Do not store password"

Testing:

Option 1: Watch the script

1. Bring up the properties of the scheduled task.
2. Change from "Run whether user is logged on or not" to "Run only when user is logged on"

Option 2: Get a transcript

Additional Resources:

Scripts:

param(
    [Parameter(Mandatory=$true)]
    [string]$Path,
    [Parameter(Mandatory=$true)]
    [string]$password
    )

    # Convert the password to a secure string
    $SecurePassword = $password | ConvertTo-SecureString -AsPlainText -Force
    
    # Store the credential in the path
    $SecurePassword | ConvertFrom-SecureString | Out-File $Path
    
    # Write What we did
    Write-Host "Wrote password to $path"    
    
<# 
.SYNOPSIS
Stores a password in a file on the local computer for retrevial by scripts.

.DESCRIPTION
Used for securely storing a password on a machine for use with automated scripts.

Takes a password and encrypts it using the local account, then stores that password in a file you specify.
Only the account that creates the output file can decrypt the password stored in the file.

.PARAMETER Path
Path and file name for the password file that will be created.

.PARAMETER Password
Plain text version of password.

.OUTPUTS
File Specified in Path variable will contain an encrypted version of the password.

.EXAMPLE
.\New-StoredCredential.ps1 -Path c:\scripts\O365Account.txt -Password "Password123"

Puts the encrypted version of Password123 into the c:\scripts\O365Account.txt file
#>

# Constants
[string]$FileAppend = (Get-Date -Format mmddyyyy_) + (Get-Random -Maximum 9999)
$OutputFile = "C:\scripts\output" + $FileAppend + ".csv"
$Username = "admin@company.onmicrosoft.com"
$RecipientCSV = "c:\scripts\recipients.csv"
$PasswordPath = "c:\scripts\password.txt"

# Read the password from the file and convert to SecureString
Write-Host "Getting password from $passwordpath"
$SecurePassword = Get-Content $PasswordPath | ConvertTo-SecureString

# Build a Credential Object from the password file and the $username constant
$Credential = New-Object System.Management.Automation.PSCredential -ArgumentList $Username, $SecurePassword

# Open a session to O365
$O365Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $Credential -Authentication Basic -AllowRedirection
import-pssession $O365session

# Get the Recipients to work with
$Recipients = Import-Csv $RecipientCSV

# Get the Mailbox Statistics
$Recipients | Foreach {
    Get-Mailboxstatistics -Identity $_.primarysmtpaddress.tostring() | Select-Object Identity,DeletedItemCount,TotalDeletedItemSize,TotalItemSize | Export-Csv $OutputFile -Append 
}

<# 
.SYNOPSIS
Simple Example Script that can be run in an automated manner against Exchange Online

.DESCRIPTION
Simple Example script for runing an automated task against Exchange Online.
     * All output/input files are defined in the #Constatns section
     * Connects to O365 using password stored on the local machine
     * Imports list of recipients from a CSV file
     * Get Mailbox Statistics information and exports to CSV

.INPUTS
recipients.csv - Csv of recipients to gather data on expected to include PrimarySMTPAddress property
password.txt   - Encrypted password for O365 account you can use New-StoredCredentials.ps1 to create this file

.OUTPUTS
A CSV file with the requested mailbox statistics information.  Will be stamped with the date and a random number to make it unique. 

.EXAMPLE
.\Start-AutomatedBasicScript.ps1

#>

# Constants
[string]$FileAppend = (Get-Date -Format mmddyyyy_) + (Get-Random -Maximum 9999)
$OutputFile = "C:\scripts\output" + $FileAppend + ".csv"
$Username = "admin@contoso.onmicrosoft.com"
$LogFile = "C:\scripts\testing.log"
$ExportRecipients = "c:\scripts\recipients.csv"
$PasswordPath = "c:\scripts\password.txt"


# Writes output to a log file with a time date stamp
Function Write-Log {
    Param ([string]$string)
    
    # Get the current date
    [string]$date = Get-Date -Format G
        
    # Write everything to our log file
    ( "[" + $date + "] - " + $string) | Out-File -FilePath $LogFile -Append
    
    # If NonInteractive true then supress host output
    if (!($NonInteractive)){
        ( "[" + $date + "] - " + $string) | Write-Host
    }
}

# Setup a new O365 Powershell Session
Function New-CleanO365Session {
    
    # If we don't have a credential then prompt for it
    $i = 0
    while (($Credential -eq $Null) -and ($i -lt 5)){
        $script:Credential = Get-Credential -Message "Please provide your Exchange Online Credentials"
        $i++
    }
    
    # If we still don't have a credentail object then abort
    if ($Credential -eq $null){
        Write-log "[Error] - Failed to get credentials"
        Write-Error -Message "Failed to get credentials" -ErrorAction Stop
    }

    Write-Log "Removing all PS Sessions"

    # Destroy any outstanding PS Session
    Get-PSSession | Remove-PSSession -Confirm:$false
    
    # Force Garbage collection just to try and keep things more agressively cleaned up due to some issue with large memory footprints
    [System.GC]::Collect()
    
    # Sleep 15s to allow the sessions to tear down fully
    Write-Log ("Sleeping 15 seconds for Session Tear Down")
    Start-sleep -seconds 15

    # Clear out all errors
    $Error.Clear()
    
    # Create the session
    Write-Log "Creating new PS Session"
    
    $session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri "https://outlook.office365.com/powershell-liveid/" -Credential $Credential -Authentication Basic -AllowRedirection
        
    # Check for an error while creating the session
    if ($Error.Count -gt 0){
    
        Write-Log "[ERROR] - Error while setting up session"
        Write-log $Error
        
        # Increment our error count so we abort after so many attempts to set up the session
        $ErrorCount++
        
        # if we have failed to setup the session > 3 times then we need to abort because we are in a failure state
        if ($ErrorCount -gt 3){
        
            Write-log "[ERROR] - Failed to setup session after multiple tries"
            Write-log "[ERROR] - Aborting Script"
            exit
        
        }
        
        # If we are not aborting then sleep 60s in the hope that the issue is transient
        Write-Log "Sleeping 60s so that issue can potentially be resolved"
        Start-sleep -seconds 60
        
        # Attempt to set up the sesion again
        New-CleanO365Session
    }
    
    # If the session setup worked then we need to set $errorcount to 0
    else {
        $ErrorCount = 0
    }
    
    # Import the PS session
    $null = Import-PSSession $session -AllowClobber
    
    # Set the Start time for the current session
    Set-Variable -Scope script -Name SessionStartTime -Value (Get-Date)
}

##### Main #####

# Read the password from the file and convert to SecureString
Write-log "Getting password from $passwordpath"
$SecurePassword = Get-Content $PasswordPath | ConvertTo-SecureString

# Build a Credential Object from the password file and the $username constant
$Credential = New-Object System.Management.Automation.PSCredential -ArgumentList $Username, $SecurePassword

# Connect to O365
New-CleanO365Session

# Get the Recipients to work with
Write-Log "Getting Recipients"
$Recipients = invoke-command -session (get-pssession) -scriptblock {get-mailbox -resultsize unlimited | select-object -property DisplayName,Identity,PrimarySMTPAddress}

# Export them to CSV for documentation
Write-Log "Exporting " + $Recipients.count + " to csv " + $ExportRecipients
$Recipients | Export-Csv $ExportRecipients

# Call Start-RobustCloudCommand to gather the data
# https://blogs.technet.microsoft.com/exchange/2015/11/02/running-powershell-cmdlets-for-large-numbers-of-users-in-office-365/
C:\temp\Start-RobustCloudCommand.ps1 -Agree -LogFile $LogFile -Recipients $Recipients -ScriptBlock { Get-Mailboxstatistics -Identity $_.primarysmtpaddress.tostring() | Select-Object Identity,DeletedItemCount,TotalDeletedItemSize,TotalItemSize | Export-Csv $OutputFile -Append } -Credential $Credential

<# 
.SYNOPSIS
Example Script that can be run in an automated manner against Exchange Online

.DESCRIPTION
Example script for runing an automated task against Exchange Online.
     * All output/input files are defined in the #Constatns section
     * Connects to O365 using password stored on the local machine
     * Gets list of recipients from O365
     * Get Mailbox Statistics information and exports to CSV using a robust connection method

.OUTPUTS
A CSV file with the requested mailbox statistics information.  Will be stamped with the date and a random number to make it unique. 

.EXAMPLE
.\Start-AutomatedScript.ps1

#>

I have been doing Exchange support for Microsoft since June 2001.  When Exchange 2007 came out and we introduced this thing called PowerShell I dove right in.  Even wrote my first largish (100+ line) script before 2007 even shipped.

Since then I have taken a practical approach to PowerShell focusing on fixing problems, filling deficits, and enabling something new.  With that in mind this blog is going to strive do the following things:

• Provide practical, useful PowerShell scripts that are well documented and clearly written
• Provide them in "spell" format.  You will find this very similar to a cooking recipe where it is clear what you need, how long it will take, and how to do it.
• Be reasonably responsive to feedback ... I do have a day job here ... :)

The sample scripts are not supported under any Microsoft standard support
program or service. The sample scripts are provided AS IS without warranty
of any kind. Microsoft further disclaims all implied warranties including, without
limitation, any implied warranties of merchantability or of fitness for a particular
purpose. The entire risk arising out of the use or performance of the sample scripts
and documentation remains with you. In no event shall Microsoft, its authors, or
anyone else involved in the creation, production, or delivery of the scripts be liable
for any damages whatsoever (including, without limitation, damages for loss of business
profits, business interruption, loss of business information, or other pecuniary loss)
arising out of the use of or inability to use the sample scripts or documentation,
even if Microsoft has been advised of the possibility of such damages.

 Otherwise I look forward to sharing all of the little solutions I have built up over the years.  If you have a question about a script, or a problem you think PowerShell could help you solve feel free to comment/ask, I will do my best to answer it, provide a solution, or point you at one.

- Matt - Resident PowerShell Wizard