emailuwpmapi

Does UWP mail app support Simple MAPI Function call from desktop app?

Is there any good way to launch UWP mail app through MAPISendMail function with file attachments from desktop app? mailto: protocol will launch but it doesn't attach files...

Update 2022-12-06:

To access Windows Runtime API from .NET Framework app, check: Call Windows Runtime APIs in desktop apps - Windows apps | Microsoft Learn

Edit csproj and add <TargetPlatformVersion>8.0</TargetPlatformVersion>

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <TargetPlatformVersion>8.0</TargetPlatformVersion>
  </PropertyGroup>
</Project>

And also add Windows reference. HintPath is mandatory and its important file Windows.winmd is included in Windows 10 SDK.

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  <ItemGroup>
    <Reference Include="Windows">
      <HintPath>C:\Program Files (x86)\Windows Kits\10\UnionMetadata\10.0.19041.0\Windows.winmd</HintPath>
    </Reference>
    <Reference Include="System.Runtime.WindowsRuntime" />
  </ItemGroup>

</Project>

And code:

namespace ConsoleApp76
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var file = StorageFile.GetFileFromPathAsync(@"C:\filepath").AsTask().Result;
            Console.WriteLine(SharedStorageAccessManager.AddFile(file));
        }
    }
}

A sharing token will be retrieved in string.

7808B122-02DD-4996-A22D-C1D9EEC880E4
Solution

  • You can do it like this: mailto:?ms-attachments=token1,token2,...

    Whereas the tokens have been created with SharedStorageAccessManager.AddFile() for the respective files you want to attach.

    https://learn.microsoft.com/en-us/uwp/api/Windows.ApplicationModel.DataTransfer.SharedStorageAccessManager

    Note that not all email clients support this format, but the built-in Windows 10 Mail app does support it.