If you have a list of email addresses from another address book source, you can bulk add these to your address book. Before you begin, extract a comma-separated list of email addresses from your external source of contacts.
To bulk upload email addresses
Step 1
Click your avatar and select profile, then select the address book tab.
Step 2
Click the plus icon – this is where you can add new email addresses either one-by-one, or in bulk.
Step 2
Paste the comma-separated list of email addresses, then press tab.
Step 3
Click add.
You can find more address book tips and tricks here.