Export AD username based on e-mail address

Question

Hello,
I'm very new to powershell. I'm looking for a script that can export sAMAccountName based on what the users e-mail address is.
I have a *.csv file with 180 e-mailaddresses and I want powershell to ask Active Directory what the corresponding sAMAccountName is for each of these e-mail adresses. The e-mail address is present in the 'mail' attribute in Active Directory. 
Then I want to export the sAMAccountName's to another *.csv file
How would that script look like?

Answer 1

Hi,
This will do what you're after:
Import-Csv .\emailAddresses.csv | ForEach {
Get-ADUser -Filter "EmailAddress -eq '$($_.EmailAddress)'" | Select SamAccountName
Note that you'll need the Active Directory module available to run this.
EDIT: If you're happy with the output, you can pipe the results to CSV using this:
Import-Csv .\emailAddresses.csv | ForEach {
Get-ADUser -Filter "EmailAddress -eq '$($_.EmailAddress)'" | Select SamAccountName
} | Export-Csv .\userNames.csv -NoTypeInformation
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