populateDistributionGroup.ps1

<#

Author: Lucas Halbert <contactme@lhalbert.xyz>
Date Written: 08/18/2017
Date Modified: 08/31/2017
Version: 0.3
Description: Imports a CSV file with names and emails into a specified distribution group

Revision History:
        08/31/2017 c0.3 - Add Try/Catchs and logging to script.

        08/30/2017 v0.2 - Add Header option Import-Csv.
                          Fix quotation problems with Write-Output

        08/18/2017 v0.1 - Inital Draft
#>

# Gather paramters
param(
    [Parameter(Mandatory=$true)][string]$CSVFile,
    [Parameter(Mandatory=$true)][string]$DistributionGroup
)

# Variables
$DistributionGroupOU="OU=DG,OU=Contacts,DC=domain,DC=tld"
$LogFile="C:\temp\PopulateDistributionGroup-$(Get-Date -Format "yyyyMMdd-HHmm").log"

# Check if CSVFile exists
if (!(Test-path $CSVFile)) {
    throw [System.IO.FileNotFoundException] "$(Get-Date): ERROR: File not found. ($CSVFile)" | Out-File $LogFile -Append
}

# Check if DistributionGroup exists
if (!(Get-DistributionGroup -Identity $DistributionGroup)) {
    throw "$(Get-Date): ERROR: DistributionGroup not found. ($DistributionGroup)" | Out-File $LogFile -Append
}

# Get all members of DistributionGroup
$members=Get-DistributionGroupMember -Identity $DistributionGroup | select -expand EmailAddresses

# Perform import of CSVFile to DistributionGroup
Import-Csv $CSVFile -Header NAME,EMAILADDRESS | ForEach-Object {
    # Check if contact already exists. If not, create new contact
    Try
    {
        # Check if contact already exists
        Get-Contact -Identity $_.EMAILADDRESS -ErrorAction Stop | Out-File $LogFile -Append
        "$(Get-Date): INFO: $_.EMAILADDRESS is already a contact" | Out-File $LogFile -Append
    }
    Catch
    {
        Try
        {
            # Create new mail contact in OU
            New-MailContact -OrganizationalUnit $DistributionGroupOU -Name $_.NAME -ExternalEmailAddress $_.EMAILADDRESS -ErrorAction Stop
            "$(Get-Date): SUCCESS: Contact has been created for$_.EMAILADDRESS" | Out-File $LogFile -Append
        }
        Catch
        {
            "$(Get-Date): ERROR: Failed to create contact for $_.EMAILADDRESS" | Out-File $LogFile -Append
        }
    }


    # Check if contact is a member of distribution group. if not, add member to distribution group
    if ($members -contains $_.EMAILADDRESS) {
        "$(Get-Date): INFO: $_.EMAILADDRESS is already a member of $DistributionGroup" | Out-File $LogFile -Append
    } else {
        Try
        {
            Add-DistributionGroupMember -Identity $DistributionGroup -Member $_.EMAILADDRESS -ErrorAction Stop
            "$(Get-Date): SUCCESS: $_.EMAILADDRESS has been add to $DistributionGroup" | Out-File $LogFile -Append
        }
        Catch
        {
            "$(Get-Date): ERROR: Failed to add $_.EMAILADDRESS to $DistributionGroup" | Out-File $LogFile -Append
        }
    }
}