O365 – Bulk import of Contacts

In Office 365 we can easily import contacts from a CSV file vs having to create them 1 by 1. The first step in doing so is to connect to our Tenant using Azure PowerShell. To do this launch Azure PS as Administrator, you should get a window as shown below.

The next step is to do the following:

Import-Module MSOnline
$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session

Once we run the second command it will prompt for user credentials. Enter your login info for O365 and click okay. You will be taken back to a prompt.

After we enter in the 3rd and then 4th command you will see the commands importing in O365.

If we login to the Office Admin Center and expand Users -> Contacts we can see that we have no contacts listed for our domain. To import contacts from a CSV file we can run the command below:
This is the command run:

$New = Import-Csv C:\ExternalContacts.csv|%{New-MailContact -Name $_.Name -DisplayName $_.Name -ExternalEmailAddress $_.ExternalEmailAddress -FirstName $_.FirstName -LastName $_.LastName}

You can just change the file path to where your CSV file is stored.
Once successfully run, it will take a few minutes depending on the number of contacts to create. You should be returned back to the prompt when done. If a contact does exist then you will receive red lines with errors saying the contact exists.