Need Help - Adding Alias Addresses to Mail Users in O365

I have a spreadsheet with three columns; Name, Email Address (already in O365) and Secondary Email Address.

I need to add the SECONDARY EMAIL ADDRESSES to the users in Office 365 via a script or command but I am having no luck, can you help me?

Thanks

You will need to set the users mailbox to add an address.

Set-Mailbox “User″ -EmailAddresses @{add=”Newaddress@domain.com”}

So you would want something like:

$csv = import-csv file.csv
foreach($users in $csv)
{
set-mailbox $emailaddress -emailaddresses @{add="$secondaryemailaddress"}
}

I would do some testing with this though, as I do not have a O365 environment to test this on.

i.e. try:
set-mailbox $emailaddress -emailaddresses @{add=“$secondaryemailaddress”}
with one user and see if it works.

You will need to get a pssession into the exchange part of O365 to be able to do this.