To export the list of users and emails addresses from Office 365 along with the first and last name of the users:

1. Start PowerShell
2. Run the following commands
   $LiveCred = Get-Credential 
   $Session = New-PSSession -ConfigurationName Microsoft.Exchange – ConnectionUri https://ps.outlook.com/powershell/ -Credential $LiveCred – Authentication Basic -AllowRedirection 
   Import-PSSession $Session

3. To export

Get-Mailbox -ResultSize Unlimited |Select-Object DisplayName,PrimarySmtpAddress, @{Name=”EmailAddresses”;Expression={$_.EmailAddresses |Where-Object {$_.PrefixString -ceq “smtp”} | ForEach-Object {$_.SmtpAddress}}} | Export-Csv c:\email-addresses.csv