Updating Mail Server Host Name in Outlook (Windows)

• Open Outlook for Windows.

• Click on the top menu File > Accounts Settings > Accounts Settings.

• Select the desired email account and click on Change.

• Under "Mail Server", or * Under "Server Information",
  Delete the previous name, and type the new server host name.
  1- In Incoming Server
  2- In Outgoing Server

• Click Next, let Outlook test the settings and close the window.

• Click on Finish to close the window and save the new settings.

• Click on Close.

If still using POP, and you have set up to leave mail on the server for X days: Outlook will re-download the mail present on the server.

Support for Outlook for Windows/Android: https://support.microsoft.com/en-us/office/how-to-get-support-for-outlook-com-f5482a98-616c-4d44-b7c5-8aaaadf5c11a