diff --git a/src/libraries/System.Net.Mail/src/Resources/Strings.resx b/src/libraries/System.Net.Mail/src/Resources/Strings.resx
index a72e327927cce..dd4d31fb2a9cb 100644
--- a/src/libraries/System.Net.Mail/src/Resources/Strings.resx
+++ b/src/libraries/System.Net.Mail/src/Resources/Strings.resx
@@ -334,4 +334,7 @@
   <data name="SmtpGetIisPickupDirectoryNotSupported" xml:space="preserve">
     <value>IIS delivery is not supported.</value>
   </data>
+  <data name="SystemNetMailNotSupported" xml:space="preserve">
+    <value>System.Net.Mail is not supported on this platform.</value>
+  </data>
 </root>
diff --git a/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj b/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj
index 9567cbde45048..fb158da2c4e1a 100644
--- a/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj
+++ b/src/libraries/System.Net.Mail/src/System.Net.Mail.csproj
@@ -1,10 +1,11 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)-Windows_NT;$(NetCoreAppCurrent)-Unix</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-Windows_NT;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Browser</TargetFrameworks>
     <Nullable>enable</Nullable>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetsBrowser)' == 'true'">SR.SystemNetMailNotSupported</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetsBrowser)' != 'true'">
     <Compile Include="System\Net\Base64Stream.cs" />
     <Compile Include="System\Net\Mime\MimePart.cs" />
     <Compile Include="System\Net\Mime\Base64WriteStateInfo.cs" />
@@ -119,7 +120,7 @@
              Link="Common\System\HexConverter.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition="'$(TargetsUnix)'=='true'">
+  <ItemGroup Condition="'$(TargetsUnix)' == 'true' and '$(TargetsBrowser)' != 'true'">
     <Compile Include="$(CommonPath)System\Net\ContextAwareResult.Unix.cs"
              Link="Common\System\Net\ContextAwareResult.Unix.cs" />
     <Compile Include="$(CommonPath)System\Net\ContextFlagsAdapterPal.Unix.cs"
diff --git a/src/libraries/System.Net.Mail/tests/Functional/AssemblyInfo.cs b/src/libraries/System.Net.Mail/tests/Functional/AssemblyInfo.cs
index f124e7754138a..07cb894602831 100644
--- a/src/libraries/System.Net.Mail/tests/Functional/AssemblyInfo.cs
+++ b/src/libraries/System.Net.Mail/tests/Functional/AssemblyInfo.cs
@@ -5,3 +5,4 @@
 using Xunit;
 
 [assembly: ActiveIssue("https://github.com/dotnet/runtime/issues/34690", TestPlatforms.Windows, TargetFrameworkMonikers.Netcoreapp, TestRuntimes.Mono)]
+[assembly: SkipOnMono("System.Net.Mail is not supported on wasm", TestPlatforms.Browser)]
diff --git a/src/libraries/System.Net.Mail/tests/Unit/AssemblyInfo.cs b/src/libraries/System.Net.Mail/tests/Unit/AssemblyInfo.cs
new file mode 100644
index 0000000000000..bf0dd949e4523
--- /dev/null
+++ b/src/libraries/System.Net.Mail/tests/Unit/AssemblyInfo.cs
@@ -0,0 +1,7 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Xunit;
+
+[assembly: SkipOnMono("System.Net.Mail is not supported on wasm", TestPlatforms.Browser)]
diff --git a/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj b/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj
index d4da9df33459e..6c8cdc274e083 100644
--- a/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj
+++ b/src/libraries/System.Net.Mail/tests/Unit/System.Net.Mail.Unit.Tests.csproj
@@ -6,6 +6,7 @@
     <Nullable>annotations</Nullable>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="AssemblyInfo.cs" />
     <Compile Include="Base64EncodingTest.cs" />
     <Compile Include="ByteEncodingTest.cs" />
     <Compile Include="EightBitStreamTest.cs" />
diff --git a/src/libraries/tests.proj b/src/libraries/tests.proj
index f5b47857a2c20..d481b5d4e0d6f 100644
--- a/src/libraries/tests.proj
+++ b/src/libraries/tests.proj
@@ -24,7 +24,6 @@
     <!-- Builds and runs but fails hard enough to not produce any output XML -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Configuration.ConfigurationManager\tests\System.Configuration.ConfigurationManager.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Http.Json\tests\FunctionalTests\System.Net.Http.Json.Functional.Tests.csproj" />
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Mail\tests\Functional\System.Net.Mail.Functional.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.NetworkInformation\tests\FunctionalTests\System.Net.NetworkInformation.Functional.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.WebClient\tests\System.Net.WebClient.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.WebSockets\tests\System.Net.WebSockets.Tests.csproj" />
@@ -74,7 +73,6 @@
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Memory\tests\System.Memory.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Http\tests\FunctionalTests\System.Net.Http.Functional.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Http\tests\UnitTests\System.Net.Http.Unit.Tests.csproj" />
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Mail\tests\Unit\System.Net.Mail.Unit.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.NameResolution\tests\FunctionalTests\System.Net.NameResolution.Functional.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.NameResolution\tests\PalTests\System.Net.NameResolution.Pal.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Ping\tests\FunctionalTests\System.Net.Ping.Functional.Tests.csproj" />