diff --git a/src/Backend/AutopilotMonitor.Functions.Tests/EmailChannelProviderTests.cs b/src/Backend/AutopilotMonitor.Functions.Tests/EmailChannelProviderTests.cs
index dfe7d925..7dc55600 100644
--- a/src/Backend/AutopilotMonitor.Functions.Tests/EmailChannelProviderTests.cs
+++ b/src/Backend/AutopilotMonitor.Functions.Tests/EmailChannelProviderTests.cs
@@ -182,7 +182,7 @@ public class EmailChannelProviderTests
         var result = await service.SendAlertWithResultAsync("ops@example.invalid; second@example.invalid", Alert());
 
         Assert.True(result.Success);
-        Assert.Equal("Sent to 2 recipient(s).", result.Message);
+        Assert.Equal("Sent to 2 recipient(s). Provider status: sent, id abc,abc.", result.Message);
         Assert.Equal(2, handler.Bodies.Count);
         Assert.Contains("\"to\":[{\"email\":\"ops@example.invalid\"", handler.Bodies[0]);
         Assert.Contains("\"subject\":\"[Autopilot Monitor] Error: Ops Alert: Platform/PushDeliveryFailed\"", handler.Bodies[0]);
@@ -198,6 +198,7 @@ public class EmailChannelProviderTests
         var rejected = await service.SendAlertWithResultAsync("ops@example.invalid", Alert());
         Assert.False(rejected.Success);
         Assert.Contains("accepted 0 of 1", rejected.Message);
+        Assert.Contains("Provider status: rejected", rejected.Message);
 
         var (unconfigured, _) = Sender(new StubHandler(), apiKey: "");
         var skipped = await unconfigured.SendAlertWithResultAsync("ops@example.invalid", Alert());
diff --git a/src/Backend/AutopilotMonitor.Functions/Services/EmailService.cs b/src/Backend/AutopilotMonitor.Functions/Services/EmailService.cs
index 27202802..e2527065 100644
--- a/src/Backend/AutopilotMonitor.Functions/Services/EmailService.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Services/EmailService.cs
@@ -25,6 +25,16 @@ namespace AutopilotMonitor.Functions.Services;
 /// <c>Email:FromName</c> (default <see cref="DefaultFromName"/>).
 /// </para>
 /// </summary>
+/// <summary>
+/// What the provider answered for one message: accepted (sent/queued/scheduled) or not, its
+/// status word, its message id (to look the mail up in the provider's activity log) and the
+/// rejection reason when it refused.
+/// </summary>
+public sealed record EmailSendOutcome(bool Accepted, string? Status, string? ProviderId, string? RejectReason)
+{
+    public static readonly EmailSendOutcome NotSent = new(false, null, null, null);
+}
+
 public class EmailService : IEmailService, IOffboardFarewellEmailSender
 {
     public const string ApiKeyConfigKey = "Email:ApiKey";
@@ -75,12 +85,12 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
             return false;
         }
 
-        var sent = await SendViaMandrillAsync(
+        var sent = (await SendViaMandrillAsync(
             toEmail,
             EmailTemplates.PreviewApprovedSubject,
             await _templates.GetHtmlAsync(EmailTemplateKind.Welcome, domainName, ct),
             tag: "welcome",
-            ct);
+            ct)).Accepted;
 
         if (sent)
         {
@@ -119,12 +129,12 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
             return false;
         }
 
-        var sent = await SendViaMandrillAsync(
+        var sent = (await SendViaMandrillAsync(
             toEmail,
             EmailTemplates.OffboardingFarewellSubject,
             await _templates.GetHtmlAsync(EmailTemplateKind.Farewell, domainName, ct),
             tag: "offboarding-farewell",
-            ct);
+            ct)).Accepted;
 
         if (sent)
         {
@@ -149,7 +159,7 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
             ? await _templates.GetHtmlAsync(kind, domainName, ct)
             : EmailTemplateService.Render(draftHtml, domainName);
 
-        var sent = await SendViaMandrillAsync(toEmail, EmailTemplateService.Subject(kind), html, tag: "test", ct);
+        var sent = (await SendViaMandrillAsync(toEmail, EmailTemplateService.Subject(kind), html, tag: "test", ct)).Accepted;
         if (sent)
             _logger.LogInformation("{Kind} test email sent to {ToEmail} (draft={IsDraft})", kind, toEmail, draftHtml is not null);
         return sent;
@@ -163,15 +173,15 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
     /// (<see cref="Notifications.EmailNotificationService"/>) on the same provider path as the
     /// transactional mails. Returns true when the provider accepted it. Never throws.
     /// </summary>
-    public virtual async Task<bool> SendMessageAsync(string toEmail, string subject, string html, string tag, CancellationToken ct = default)
+    public virtual async Task<EmailSendOutcome> SendMessageAsync(string toEmail, string subject, string html, string tag, CancellationToken ct = default)
     {
         if (!IsConfigured)
         {
             _logger.LogWarning("{ConfigKey} not configured — skipping {Tag} mail", ApiKeyConfigKey, tag);
-            return false;
+            return EmailSendOutcome.NotSent;
         }
         if (string.IsNullOrWhiteSpace(toEmail))
-            return false;
+            return EmailSendOutcome.NotSent;
         return await SendViaMandrillAsync(toEmail, subject, html, tag, ct);
     }
 
@@ -179,9 +189,10 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
     /// The only provider-specific code path. Posts a Mandrill <c>messages/send</c> request and
     /// interprets the per-recipient result array: <c>sent</c>/<c>queued</c>/<c>scheduled</c>
     /// count as success, <c>rejected</c>/<c>invalid</c> as failure (with the provider's
-    /// <c>reject_reason</c> in the warning). Never throws.
+    /// <c>reject_reason</c> in the warning). Never throws; the outcome carries the provider's status
+    /// word and message id so a mail that never arrived can be looked up in its activity log.
     /// </summary>
-    private async Task<bool> SendViaMandrillAsync(string toEmail, string subject, string html, string tag, CancellationToken ct)
+    private async Task<EmailSendOutcome> SendViaMandrillAsync(string toEmail, string subject, string html, string tag, CancellationToken ct)
     {
         try
         {
@@ -210,7 +221,7 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
                 _logger.LogWarning(
                     "Email provider returned {StatusCode} for {Tag} mail to {ToEmail}: {Body}",
                     (int)response.StatusCode, tag, toEmail, Truncate(body));
-                return false;
+                return EmailSendOutcome.NotSent;
             }
 
             var results = JsonSerializer.Deserialize<MandrillSendResult[]>(body, JsonOptions);
@@ -220,7 +231,7 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
                 _logger.LogWarning(
                     "Email provider returned an empty result for {Tag} mail to {ToEmail}: {Body}",
                     tag, toEmail, Truncate(body));
-                return false;
+                return EmailSendOutcome.NotSent;
             }
 
             if (!IsAcceptedStatus(result.Status))
@@ -228,15 +239,15 @@ public class EmailService : IEmailService, IOffboardFarewellEmailSender
                 _logger.LogWarning(
                     "Email provider did not accept {Tag} mail to {ToEmail}: status={Status} reason={Reason}",
                     tag, toEmail, result.Status, result.RejectReason ?? "n/a");
-                return false;
+                return new EmailSendOutcome(false, result.Status, result.Id, result.RejectReason);
             }
 
-            return true;
+            return new EmailSendOutcome(true, result.Status, result.Id, null);
         }
         catch (Exception ex)
         {
             _logger.LogWarning(ex, "Failed to send {Tag} mail to {ToEmail}", tag, toEmail);
-            return false;
+            return EmailSendOutcome.NotSent;
         }
     }
 
diff --git a/src/Backend/AutopilotMonitor.Functions/Services/Notifications/EmailNotificationService.cs b/src/Backend/AutopilotMonitor.Functions/Services/Notifications/EmailNotificationService.cs
index fc506dcb..56357747 100644
--- a/src/Backend/AutopilotMonitor.Functions/Services/Notifications/EmailNotificationService.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Services/Notifications/EmailNotificationService.cs
@@ -1,3 +1,4 @@
+using AutopilotMonitor.Functions.Services;
 using AutopilotMonitor.Shared.Models.Notifications;
 using Microsoft.ApplicationInsights;
 using Microsoft.Extensions.Logging;
@@ -73,28 +74,31 @@ public class EmailNotificationService : IEmailChannelSender
 
         var subject = EmailAlertRenderer.Subject(alert);
         var html = EmailAlertRenderer.Html(alert);
-        var accepted = 0;
+        var outcomes = new List<EmailSendOutcome>();
         foreach (var address in addresses.Take(MaxRecipients))
-        {
-            if (await _email.SendMessageAsync(address, subject, html, Tag).ConfigureAwait(false))
-                accepted++;
-        }
+            outcomes.Add(await _email.SendMessageAsync(address, subject, html, Tag).ConfigureAwait(false));
 
-        var attempted = Math.Min(addresses.Count, MaxRecipients);
-        Track(accepted == attempted ? "delivered" : accepted == 0 ? "failed" : "partial", attempted, accepted);
+        var attempted = outcomes.Count;
+        var accepted = outcomes.Count(o => o.Accepted);
+        // The provider's status word and message ids: "queued" (deferred by the provider) is not
+        // "sent", and the id is what its activity log is searched by when a mail never arrives.
+        var statuses = string.Join(",", outcomes.Where(o => o.Status != null).Select(o => o.Status!).Distinct());
+        var ids = string.Join(",", outcomes.Where(o => o.ProviderId != null).Select(o => o.ProviderId!));
+        Track(accepted == attempted ? "delivered" : accepted == 0 ? "failed" : "partial", attempted, accepted, statuses, ids);
         if (accepted < attempted)
             _logger.LogWarning("E-mail alert {EventType}: provider accepted {Accepted} of {Attempted} recipient(s)", alert.EventType, accepted, attempted);
 
+        var detail = statuses.Length > 0 ? $" Provider status: {statuses}{(ids.Length > 0 ? $", id {ids}" : string.Empty)}." : string.Empty;
         return new WebhookTestResult
         {
             Success = accepted > 0,
-            Message = accepted == attempted
+            Message = (accepted == attempted
                 ? $"Sent to {accepted} recipient(s)."
-                : $"The e-mail provider accepted {accepted} of {attempted} recipient(s) — see the backend log for the rejection.",
+                : $"The e-mail provider accepted {accepted} of {attempted} recipient(s) — see the backend log for the rejection.") + detail,
         };
     }
 
-    private void Track(string outcome, int attempted, int accepted)
+    private void Track(string outcome, int attempted, int accepted, string statuses = "", string ids = "")
     {
         try
         {
@@ -103,6 +107,8 @@ public class EmailNotificationService : IEmailChannelSender
                 ["outcome"] = outcome,
                 ["attempted"] = attempted.ToString(),
                 ["accepted"] = accepted.ToString(),
+                ["status"] = statuses,
+                ["providerIds"] = ids,
             });
         }
         catch