DavMail + Office365

You can find your own URL by testing your account in https://testconnectivity.microsoft.com Then, search in the bunch of information to find it.

Sometimes, your company has its own servers and address and outlook.office365.com is not the way to go !

This is now covered in the DavMail FAQ:

Office 365

Office 365 EWS endpoint is now standard for all customers: https://outlook.office365.com/EWS/Exchange.asmx

Also make sure you set mode to EWS in settings

Is Office 365 modern authentication / MFA supported ?

Office 365 modern authentication is available with the following modes:

• O365Interactive: will open an authentication window to let you enter your credentials and go through MFA check and
• O365Modern: same logic as O365Interactive, but use client provided credentials for Oauth negotiation, trigger PhoneApp MFA check transparently

Personally I didn't have any joy with O365Modern, but O365Interactive worked perfectly.

If you always get error message like "authentication failed All network interface down davmail", maybe u should login https://outlook.office365.com/EWS/Exchange.asmx firstly, and it will tell you that:

You have created a service.

To test this service, you will need to create a client and use it to call the service. You can do this using the svcutil.exe tool from the command line with the following syntax:


svcutil.exe https://ch2pr19mb4024.namprd19.prod.outlook.com:444/EWS/Services.wsdl
This will generate a configuration file and a code file that contains the client class. Add the two files to your client application and use the generated client class to call the Service. For example:

C#

class Test
{
    static void Main()
    {
        HelloClient client = new HelloClient();

        // Use the 'client' variable to call operations on the service.

        // Always close the client.
        client.Close();
    }
}

Visual Basic

Class Test
    Shared Sub Main()
        Dim client As HelloClient = New HelloClient()
        ' Use the 'client' variable to call operations on the service.

        ' Always close the client.
        client.Close()
    End Sub
End Class

Then you can send mail with smtp without problems!