I have a script that updates a users name based off of a csv file. I would like to send the users a email with there new login after the script has run. Currently, the script only sends to the first user instead of the entire list. Do you have any ideal on how I can get the script to send to a email to each users with their information? 

The script already does what you ask:

$emailTo = "aaron.harris@cage.com , $CurrentEmail"

Perhaps you should aske the author to look at this for you. When you send the mail ther will not likely be a mailbox because you have just created the account.  THe mailbox will not be immediately provisioned.

why this? 

$array = @(Import-CSV "D:\Scripts\AH\NameChange2\ExportCSV\NameChange.csv") 
foreach($value in $array)
{

$CurrentEmail += $value.CurrentEmailAddress 

why this? 

$array = @(Import-CSV "D:\Scripts\AH\NameChange2\ExportCSV\NameChange.csv") 
foreach($value in $array)
{

$CurrentEmail += $value.CurrentEmailAddress 

why this? 

$array = @(Import-CSV "D:\Scripts\AH\NameChange2\ExportCSV\NameChange.csv") 
foreach($value in $array)
{

$CurrentEmail += $value.CurrentEmailAddress 

But, as noted, that email is no longer valid.  Perhaps the domain no longer exists.  No mater where and how you add it it will not receive mail.  The OP needs to use the new mail address.

What is the purpose of the way it's written as opposed to...

The email is sent to the users old address, which is listed as an alias. So the address is valid. The name change is adding an additional address but not removing the old addr

Looking closely at the script is has many logic errors that you need to fix before addressing whether it will send mail.

I cannot determine what you are trying to do from the logic. The logic is redundant or incorrect or both.

You also need to simplify and format the script to be more readable.

Why are you trying to get so many user objects.  Do the users have more than one account? Two accounts cannot have the same email in the same Exchange organization. 

Looking closely at the script is has many logic errors that you need to fix before addressing whether it will send mail.

You also need to simplify and format the script to be more readable.

What first users.  The email address is set to the mail address in each line of the CSV.

This makes no sens:

 $User1 = Get-ADUser -id  ($value.NewFirstName.substring(0, 1) + $value.NewLastName)
 $User2 = Get-ADUser -id  ($value.NewFirstName.substring(0, 2) + $value.NewLastName)
 $User3 = Get-ADUser -id  ($value.NewFirstName.substring(0, 3) + $value.NewLastName)
 
 $userUPN = Get-ADUser -filter { Emailaddress -eq $NewEmail1 }
 $userUPN = Get-ADUser -filter { Emailaddress -eq $NewEmail2 }
 
 And it will likely not work.  This could be the source of you whole proble,

Why are you doing this?  If you are trying to guess at the user ID then nothing is predictable.  You must use either the SamAccountName or DistinguishedName to identify a unique user.

Can you contact the author of this to get help.  I suspect the original may have worked but someone tried to change it and has mad it non-functional.

Here is a better formatted version so you can try and follow what is happening:

$array = @(Import-CSV "D:\Scripts\AH\NameChange2\ExportCSV\NameChange.csv")
foreach ($value in $array) {
	
	$CurrentEmail += $value.CurrentEmailAddress
	$NewEmail1 = $value.NewEmailAddress
	$NewEmail2 = $value.NewFirstName + "." + $value.Title + "." + $value.NewLastName + $EmailCengage
	
	$User1 = Get-ADUser -id  ($value.NewFirstName.substring(0, 1) + $value.NewLastName)
	$User2 = Get-ADUser -id  ($value.NewFirstName.substring(0, 2) + $value.NewLastName)
	$User3 = Get-ADUser -id  ($value.NewFirstName.substring(0, 3) + $value.NewLastName)
	
	$userUPN = Get-ADUser -filter { Emailaddress -eq $NewEmail1 }
	$userUPN = Get-ADUser -filter { Emailaddress -eq $NewEmail2 }
	
	
	
	if ($User1 -eq $null -and $userUPN -eq $null) {
		
		$NewLogin1 = $NewEmail1
		set-RemoteMailbox -Id $value.EnterPCLogin.split('\')[-1] -PrimarySmtpAddress $value.NewEmailAddress
		
		Set-ADUser -Id $value.EnterPCLogin.split('\')[-1] -GivenName $value.NewFirstName -Surname $value.NewLastName -UserPrincipalName $value.NewEmailAddress -SamAccountName ($value.NewFirstName.substring(0, 1) + $value.NewLastName) -DisplayName ($value.NewLastName + ", " + $value.NewFirstName) -Emailaddress $value.NewEmailAddress
		#-Add @{proxyAddresses = "smtp:" + $value.NewEmailAddress
		
		$Where = [array]::IndexOf($CurrentEmail, $NewEmail1)
		Write-Host "Customer Name: " $CurrentEmail[$Where]
		
		$emailFrom = "DoNotReply@cage.com"
		$emailTo = "aaron.harris@cage.com , $CurrentEmail"
		
		$subject = "Name Change Request $NewLogin1, $NewLogin2"
		$body = "Your New Login Name is  $NewLogin1, $NewLogin2"
		$body += $a.sum | Out-String
		$smtpServer = "mailhost.learning.com" # Replace with your SMTP Server IP
		$smtp = new-object Net.Mail.SmtpClient($smtpServer)
		$smtp.Send($emailFrom, $emailTo, $subject, $body)
		
		
	} Elseif ($User1 -ne $null -and $User2 -eq $null -and $userUPN2 -eq $null) {
		$NewLogin2 = $NewEmail2
		set-RemoteMailbox -Id $value.EnterPCLogin.split('\')[-1] -PrimarySmtpAddress $NewEmail2
		
		
		Set-ADUser -Id $value.EnterPCLogin.split('\')[-1]  -GivenName $value.NewFirstName -Surname $value.NewLastName -UserPrincipalName ($value.NewFirstName + "." + $value.Title + "." + $value.NewLastName + $EmailCengage) -SamAccountName ($value.NewFirstName.substring(0, 2) + $value.NewLastName)  -DisplayName ($value.NewLastName + ", " + $value.Title + $value.NewFirstName) -Emailaddress $value.EmailAddress
		#-Add @{proxyAddresses =  "smtp:"+ ($value.NewFirstName + "." + $value.Title + "." + $value.NewLastName + $Emailengage)
		#
		
		$Where = [array]::IndexOf($CurrentEmail, $NewEmail1)
		Write-Host "Customer Name: " $CurrentEmail[$Where]
		
		$emailFrom = "DoNotReply@.com"
		$emailTo = "aaron.harris@.com , $CurrentEmail"
		
		$subject = "Name Change Request $NewLogin1, $NewLogin2"
		$body = "Your New Login Name is  $NewLogin1, $NewLogin2"
		$body += $a.sum | Out-String
		$smtpServer = "mailhost.earning.com" # Replace with your SMTP Server IP
		$smtp = new-object Net.xxx.SmtpClient($smtpServer)
		$smtp.Send($emailFrom, $emailTo, $subject, $body)
		
	}
		
	write-host "First Name =" $value.NewFirstName "Last Name =" $value.NewLastName "Middle Name=" $value.Title "Login =" $value.EnterPCLogin.split('\')[-1]
	
	Write-Host "final result"
	Write-Host "user1 $User1 "
	Write-Host "user2 $User2 "
	Write-Host "user3 $User3 "
	Write-Host "UPN1 $UserUPN1"
	Write-Host "UPN1 $UserUPN2"
	
}

As you can see there is only one path that sends email.

The following wil not get you a uniquely identifiable user.

$User1 = Get-ADUser -id  ($value.NewFirstName.substring(0, 1) +$value.NewLastName)
$User2 = Get-ADUser -id  ($value.NewFirstName.substring(0, 2) +$value.NewLastName)
$User3 = Get-ADUser -id  ($value.NewFirstName.substring(0, 3) +$value.NewLastName)$userUPN = Get-ADUser -filter { Emailaddress -eq $NewEmail1 }
$userUPN = Get-ADUser -filter { Emailaddress -eq $NewEmail2 }
 

What is the purpose of the way it's written as opposed to...

$array = Import-CSV "NameChange.csv"
foreach ($value in $array) {

$CurrentEmail = $value.CurrentEmailAddres

Your wrong jrv.... What I have will work when updating the script based on Dave's response. I was able to test and confirm. Have a happy Tuesday

Depending on your organization you might be better off with using anr to find proxy addresses. I've seen many inconsistencies between proxyaddresses,mail,emailaddress attributes. 

Get-ADUser -Filter {anr -eq 'smtp:someone@domain.com'}

Depending on your organization you might be better off with using anr to find proxy addresses. I've seen many inconsistencies between proxyaddresses,mail,emailaddress attributes. 

Get-ADUser -Filter {anr -eq 'smtp:someone@domain.com'}