Note: Outlook-for-Mac information on this topic is available here.
Import to Microsoft 365
Export from Microsoft 365
Import to Outlook.com
Export from Outlook.com
Import from Gmail
Import Gmail contacts to Outlook
Import Google Calendar to Outlook
Prepare your Gmail or G Suite account for connecting to Outlook and Office 365
Export contacts out of other email services
Export Gmail contacts – See Gmail help
Export Yahoo contacts – See Yahoo import and export help
Export Thunderbird contacts – See Mozilla support.