Can't send or receive emails

For approximately the past10 days I cannot send or receive mails.  Steps I have taken to remedy this: uninstalled and reinstalled Windows 11, uninstalled and reinstalled Outlook and double checked all settings.  I attempted to do a System Restore but it willl not allow me to input a date of 11/15/25 as a restore point.  Also thinkng it was a Windows update issue, tried to unininstall updates back to previous dates, also will not allow. Any help would be greatly appreciated!