fix(ui): mirror the EWS username:password credentials rule on the SMTP page

src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Notifications/SmtpConfiguration.razor

@@ -308,6 +308,24 @@
             return;
         }
 
+        // Mirror of the same gate's credentials rule, with the identical FIRST-colon-only
+        // split: a domain-qualified user name contains no colon but a password may. This
+        // page has no preserve-if-blank behaviour — the field's value IS what gets
+        // persisted, and a blank field clears the stored credential — so the rule applies
+        // on edit as well as add, exactly as the management gate validates the effective row.
+        if (IsEwsForm)
+        {
+            var credentialParts = _credentials?.Trim().Split(':', 2) ?? [];
+            if (credentialParts.Length != 2
+                || credentialParts[0].Length == 0
+                || credentialParts[1].Length == 0)
+            {
+                _formError = "EWS credentials must be in 'username:password' form "
+                    + @"(username may be 'domain\username').";
+                return;
+            }
+        }
+
         try
         {
             if (_editingSmtp != null)

tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Pages/SmtpConfigurationPageTests.cs

@@ -182,6 +182,7 @@ public class SmtpConfigurationPageTests : BunitContext
         // The forced auth type is only observable through what gets persisted: the row
         // loaded as OAuth2 must save as Basic because EWS supports Basic only.
         cut.Find("input[type=text]").Change("https://mail.example.com/ews/exchange.asmx");
+        cut.Find("input[type=password]").Change(@"dom\user:pw");
         ClickSave(cut);
 
         cut.WaitForAssertion(() =>
@@ -233,6 +234,47 @@ public class SmtpConfigurationPageTests : BunitContext
         repo.DidNotReceive().SaveChangesAsync();
     }
 
+    [Fact]
+    public void Save_WithEwsTransportAndCredentialsWithoutColon_ShowsFormErrorAndDoesNotPersist()
+    {
+        var repo = Substitute.For<INotificationRepository>();
+        // The realistic mistake: an existing SMTP row whose credential is a bare password
+        // is flipped to Ews. Host is valid, so only the credentials rule can reject it.
+        var cut = RenderWith(repo, OAuth2Sample());
+
+        ClickEdit(cut);
+        SelectWithOption(cut, "Ews").Change("Ews");
+        cut.Find("input[type=text]").Change("https://mail.example.com/ews/exchange.asmx");
+        cut.Find("input[type=password]").Change("bare-password");
+        ClickSave(cut);
+
+        cut.WaitForAssertion(() => Assert.Contains("username:password", cut.Markup));
+        repo.DidNotReceive().UpdateSmtpConfigurationAsync(Arg.Any<SmtpConfiguration>());
+        repo.DidNotReceive().SaveChangesAsync();
+    }
+
+    [Fact]
+    public void Save_WithEwsTransportAndDomainQualifiedCredentials_Persists()
+    {
+        var repo = Substitute.For<INotificationRepository>();
+        var cut = RenderWith(repo, OAuth2Sample());
+
+        ClickEdit(cut);
+        SelectWithOption(cut, "Ews").Change("Ews");
+        cut.Find("input[type=text]").Change("https://mail.example.com/ews/exchange.asmx");
+        // A domain-qualified user name carries no colon of its own; the split takes the
+        // FIRST colon only, so a password containing colons stays intact.
+        cut.Find("input[type=password]").Change(@"dom\user:pw:with:colons");
+        ClickSave(cut);
+
+        cut.WaitForAssertion(() =>
+        {
+            repo.Received().UpdateSmtpConfigurationAsync(Arg.Is<SmtpConfiguration>(
+                c => c.Transport == "Ews" && c.Credentials == @"dom\user:pw:with:colons"));
+            repo.Received().SaveChangesAsync();
+        });
+    }
+
     [Fact]
     public void ReadOnlyView_ShowsTransportBadgeAndHidesPortAndTlsForEwsRows()
     {