cemililik · Oct 27, 2026 · Oct 27, 2026 · Oct 27, 2026 · Oct 27, 2026 · Oct 27, 2026
diff --git a/README.md b/README.md
@@ -144,6 +144,14 @@ creation does not repair existing files. The
 [realm guide](infra/keycloak/README.md#secret-continuity-and-recovery) owns setup,
 refusal, safe secret recovery and qualification details.
 
+API startup also requires the fixed
+[invitation SMTP settings and encryption key ring](docs/modules/identity/providers.md#configuration-surface-and-source-bindings).
+Prepare these operator-owned values before starting the API or demo; an older
+private file is not silently supplied with a replacement encryption key.
+Keycloak's separate
+[account-verification sender](infra/keycloak/README.md#invitation-email-and-recipient-verification)
+must also work for the complete new-recipient journey.
+
 ### 3. Prepare local HTTPS and start the applications
 
 The demo prepares a missing private 32-byte hop secret in the ignored root `.env`.

diff --git a/backend/Directory.Packages.props b/backend/Directory.Packages.props
@@ -171,6 +171,11 @@
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
   </ItemGroup>
 
+  <ItemGroup Label="Phase 03 bounded invitation SMTP (ADR-0093)">
+    <PackageVersion Include="MailKit" Version="4.18.2" />
+    <PackageVersion Include="MimeKit" Version="4.18.2" />
+  </ItemGroup>
+
   <!--
     Roslyn host packages — the analyzers under backend/analyzers/ compile against them, and
     the unit and architecture suites run those analyzers over real source.

diff --git a/backend/LearnStack.slnx b/backend/LearnStack.slnx
@@ -61,6 +61,7 @@
   </Folder>
   <Folder Name="/tests/">
     <Project Path="tests/LearnStack.Tests.AuthorizationEvidenceProbe/LearnStack.Tests.AuthorizationEvidenceProbe.csproj" />
+    <Project Path="tests/LearnStack.Tests.InvitationSmtpProbe/LearnStack.Tests.InvitationSmtpProbe.csproj" />
     <Project Path="tests/LearnStack.Tests.IdempotencyStoreProbe/LearnStack.Tests.IdempotencyStoreProbe.csproj" />
     <Project Path="tests/LearnStack.Tests.JobLifecycleProbe/LearnStack.Tests.JobLifecycleProbe.csproj" />
     <Project Path="tests/LearnStack.Tests.Unit/LearnStack.Tests.Unit.csproj" />