Make Windows Mail the default e-mail program in Windows 10 version 1709, 1803 or later

Right lick the Start button, and then click Settings. In the Windows Settings window click Apps, and then click Default apps.

  • 1

    Choose Windows Mail as the default e-mail program

    On the Default apps page, under Email, choose Windows Mail.

    Default e-mail program
  • 2

    Choose defaults for Windows Mail

    On the Default apps page, click Set defaults by app.

    Set defaults by app

    Select Windows Mail, and then click Manage.

    Select Windows Mail

    Under File type and protocol associations, select Windows Mail for .eml file extension and MAILTO protocol.

    File type and protocol associations

    To register Windows Mail as the default MAPI client, change the registry value (the Modern GUI does not allow you to do this). Right click the Start button, and then click Run. Type regedit; click OK to start Registry Editor. Find or create the HKEY_CURRENT_USER\Software\Clients\Mail key. Change the value of default parameter (REG_SZ) to Windows Mail. See picture below.

    Default MAPI client
  • 3

    Associate file types with Windows Mail

    On the Default apps page, click Choose default apps by file type.

    Choose default apps by file type

    Under Choose default apps by file type, make sure that .eml file extension is associated with Windows Mail application. To change the default program, click the extension, and then select Windows Mail.

    .eml file extension
  • 4

    Associate protocols with Windows Mail

    On the Default apps page, click Choose default apps by protocol.

    Choose default apps by protocol

    Under Choose default apps by protocol, make sure that MAILTO protocol is associated with Windows Mail application. To change the default program, click the item, and then select Windows Mail.

    MAILTO protocol

Make Windows Mail the default e-mail program in Windows 8.1 or Windows 7 (including early versions of Windows 10)

In Windows 8.1 or Windows 10 (version 1703 or earlier), right click the Start button, and then click Control Panel. On Windows 7, click the Start button, and then click Control Panel. In the Control Panel, click Programs, and then click Default Programs.

  • 1

    Choose Windows Mail as the default e-mail program

    In the Control Panel, under Default Programs, click Set program access and computer defaults.

    Set program access and computer defaults

    Under Choose a configuration, click Custom. Under Choose a default e‑mail program, click Windows Mail, and then click OK.

    Choose a default e‑mail program
  • 2

    Choose defaults for Windows Mail

    In the Control Panel, under Default Programs, click Set your default programs.

    Set your default programs

    In the list of programs, select Windows Mail. Click Set this program as default to use Windows Mail to open all file types and protocols it can open by default. Or click Choose defaults for this program to choose which file types and protocols Windows Mail opens by default.

    Select Windows Mail

    Windows Mail can be associated with .eml file extension and MAILTO protocol. Send mail checkbox is responsible for registering Windows Mail as the default MAPI client.

    Windows Mail associations
  • 3

    Associate file types and protocols with Windows Mail

    In the Control Panel, under Default Programs, click Associate a file type or protocol with a program.

    Associate a file type or protocol with a program

    Make sure that .eml file extension and MAILTO protocol are associated with Windows Mail application. To change the default program, click the extension, click Change Program, and then select Windows Mail.

    .eml file extension