diff --git a/src/AliasVault.Client/wwwroot/css/tailwind.css b/src/AliasVault.Client/wwwroot/css/tailwind.css
index 717a56931..7ebfd9c4c 100644
--- a/src/AliasVault.Client/wwwroot/css/tailwind.css
+++ b/src/AliasVault.Client/wwwroot/css/tailwind.css
@@ -772,6 +772,10 @@ video {
   margin-right: 0.25rem;
 }
 
+.ml-2 {
+  margin-left: 0.5rem;
+}
+
 .block {
   display: block;
 }
@@ -1141,6 +1145,12 @@ video {
   overscroll-behavior-y: auto;
 }
 
+.truncate {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
 .whitespace-nowrap {
   white-space: nowrap;
 }
@@ -1608,6 +1618,11 @@ video {
   color: rgb(255 255 255 / var(--tw-text-opacity));
 }
 
+.text-red-600 {
+  --tw-text-opacity: 1;
+  color: rgb(220 38 38 / var(--tw-text-opacity));
+}
+
 .opacity-0 {
   opacity: 0;
 }
@@ -1777,6 +1792,11 @@ video {
   border-color: rgb(244 149 65 / var(--tw-border-opacity));
 }
 
+.focus\:border-blue-500:focus {
+  --tw-border-opacity: 1;
+  border-color: rgb(59 130 246 / var(--tw-border-opacity));
+}
+
 .focus\:outline-none:focus {
   outline: 2px solid transparent;
   outline-offset: 2px;
@@ -1839,6 +1859,11 @@ video {
   --tw-ring-color: rgb(156 163 175 / var(--tw-ring-opacity));
 }
 
+.focus\:ring-blue-500:focus {
+  --tw-ring-opacity: 1;
+  --tw-ring-color: rgb(59 130 246 / var(--tw-ring-opacity));
+}
+
 .focus\:ring-offset-2:focus {
   --tw-ring-offset-width: 2px;
 }
@@ -2041,6 +2066,11 @@ video {
   border-color: rgb(244 149 65 / var(--tw-border-opacity));
 }
 
+.dark\:focus\:border-blue-500:focus:is(.dark *) {
+  --tw-border-opacity: 1;
+  border-color: rgb(59 130 246 / var(--tw-border-opacity));
+}
+
 .dark\:focus\:ring-blue-800:focus:is(.dark *) {
   --tw-ring-opacity: 1;
   --tw-ring-color: rgb(30 64 175 / var(--tw-ring-opacity));
@@ -2091,6 +2121,16 @@ video {
   --tw-ring-color: rgb(127 29 29 / var(--tw-ring-opacity));
 }
 
+.dark\:focus\:ring-blue-500:focus:is(.dark *) {
+  --tw-ring-opacity: 1;
+  --tw-ring-color: rgb(59 130 246 / var(--tw-ring-opacity));
+}
+
+.dark\:focus\:ring-blue-600:focus:is(.dark *) {
+  --tw-ring-opacity: 1;
+  --tw-ring-color: rgb(37 99 235 / var(--tw-ring-opacity));
+}
+
 @media (min-width: 640px) {
   .sm\:col-span-3 {
     grid-column: span 3 / span 3;
@@ -2108,6 +2148,10 @@ video {
     width: auto;
   }
 
+  .sm\:flex-row {
+    flex-direction: row;
+  }
+
   .sm\:space-x-4 > :not([hidden]) ~ :not([hidden]) {
     --tw-space-x-reverse: 0;
     margin-right: calc(1rem * var(--tw-space-x-reverse));
diff --git a/src/Tests/AliasVault.E2ETests/Common/ClientPlaywrightTest.cs b/src/Tests/AliasVault.E2ETests/Common/ClientPlaywrightTest.cs
index aa70caaf8..6f86ca21f 100644
--- a/src/Tests/AliasVault.E2ETests/Common/ClientPlaywrightTest.cs
+++ b/src/Tests/AliasVault.E2ETests/Common/ClientPlaywrightTest.cs
@@ -190,6 +190,27 @@ public class ClientPlaywrightTest : PlaywrightTest
         Assert.That(pageContent, Does.Contain("Login credentials"), "Credential not created.");
     }
 
+    /// <summary>
+    /// Logout the current user and register a new account.
+    /// </summary>
+    /// <returns>Task.</returns>
+    protected async Task LogoutAndLoginAsNewUser()
+    {
+        // Logout.
+        await NavigateUsingBlazorRouter("user/logout");
+        await WaitForUrlAsync("user/logout", "AliasVault");
+
+        // Wait and check if we get redirected to /user/login.
+        await WaitForUrlAsync("user/login");
+
+        // Reset username and password so a new random account is created.
+        TestUserUsername = string.Empty;
+        TestUserPassword = string.Empty;
+
+        // Register a new account random account.
+        await Register();
+    }
+
     /// <summary>
     /// Register a new random account.
     /// </summary>
diff --git a/src/Tests/AliasVault.E2ETests/Tests/Client/EmailDecryptionTest.cs b/src/Tests/AliasVault.E2ETests/Tests/Client/EmailDecryptionTest.cs
index 890c2eb71..c9c7ac6ea 100644
--- a/src/Tests/AliasVault.E2ETests/Tests/Client/EmailDecryptionTest.cs
+++ b/src/Tests/AliasVault.E2ETests/Tests/Client/EmailDecryptionTest.cs
@@ -88,7 +88,6 @@ public class EmailDecryptionTest : ClientPlaywrightTest
         Assert.That(emailReceived.Subject, Does.Not.Contain(textSubject), "Email subject stored as plain text in database. Check email encryption logic.");
 
         // Attempt to click on email refresh button to get new emails.
-        // Id =  recent-email-refresh
         await Page.Locator("id=recent-email-refresh").First.ClickAsync();
 
         // Wait for 1 sec
@@ -121,6 +120,47 @@ public class EmailDecryptionTest : ClientPlaywrightTest
         Assert.That(claim, Is.Null, "Claim for unknown email address domain found in database. Check if claim creation domain check is working correctly.");
     }
 
+    /// <summary>
+    /// Test that a user cannot claim an email address that is already claimed by another user.
+    /// </summary>
+    /// <returns>Async task.</returns>
+    [Test]
+    public async Task EmailDuplicateClaimTest()
+    {
+        // Create credential which should automatically create claim on server during database sync.
+        const string serviceName = "Test Service";
+        const string email = "testclaim@example.tld";
+        await CreateCredentialEntry(new Dictionary<string, string>
+        {
+            { "service-name", serviceName },
+            { "email", email },
+        });
+
+        // Assert that the claim was created on the server.
+        var claim = await ApiDbContext.UserEmailClaims.FirstOrDefaultAsync(x => x.Address == email);
+
+        // Login as new user.
+        await LogoutAndLoginAsNewUser();
+
+        // Try to claim the same email address again.
+        await CreateCredentialEntry(new Dictionary<string, string>
+        {
+            { "service-name", serviceName },
+            { "email", email },
+        });
+
+        // Assert that still only one claim exists for the email address.
+        var claimCount = await ApiDbContext.UserEmailClaims.CountAsync(x => x.Address == email);
+        Assert.That(
+            claimCount,
+            Is.LessThanOrEqualTo(1),
+            "More than one claim for email address found in database while only one should exist. Check if claim creation domain check is working correctly.");
+
+        // Assert that error is displayed on the page.
+        var pageContent = await Page.TextContentAsync("body");
+        Assert.That(pageContent, Does.Contain("The current chosen email address is already in use"), "Error message not displayed on page when trying to claim email address already claimed by another user.");
+    }
+
     /// <summary>
     /// Tear down logic for every test.
     /// </summary>