Outlook can support multiple profiles where each profile can contain different email accounts and settings, and you can choose which profile to use when starting Outlook.

To manage Outlook profiles in Windows:

• Open the Windows control panel (in Windows 10, press Start and type Control Panel)
• Make sure it's set to show All Control Panel Items
• Look for the setting called "Mail (Microsoft Outlook xxxx)" and open it
• Click Show Profiles

This will show profiles you have set up and let you add and remove profiles.

If you are going to have multiple profiles, you should check the box "Prompt for a profile to be used". This will let you choose which profile to use when starting Outlook. If you are creating multiple profiles as a temporary measure, once you've finished, you can then change that setting back so it no longer prompts you.

To create a new profile, click the "Add" button, give it a sensible name (e.g. your primary email address, or your own name), then follow the prompts to set up the first email account within that new profile.

Once you've finished, be sure to click OK in the "Mail" window so that it saves any settings you changed relating to profiles.