diff --git a/src/backend/main/java/ai/mnemosyne_systems/service/IncomingEmailService.java b/src/backend/main/java/ai/mnemosyne_systems/service/IncomingEmailService.java
index 43007fe6..becc7051 100644
--- a/src/backend/main/java/ai/mnemosyne_systems/service/IncomingEmailService.java
+++ b/src/backend/main/java/ai/mnemosyne_systems/service/IncomingEmailService.java
@@ -67,9 +67,27 @@ public IncomingEmailResult processIncomingEmail(String from, String subject, Str
             }
         }
         if (ticket == null) {
-            ticket = createTicketForIncoming(sender, subject, body);
+            List<String> incomingTraces = new ArrayList<>();
+            incomingTraces.addAll(StackTraceExtractor.extractStackTraces(body));
+            incomingTraces.addAll(StackTraceExtractor.extractStackTracesFromAttachments(attachments));
+
+            if (!incomingTraces.isEmpty()) {
+                Ticket duplicateTicket = findExistingTicketWithSameStackTrace(sender, incomingTraces);
+                if (duplicateTicket != null) {
+                    ticket = duplicateTicket;
+                    escalateTicket(ticket);
+                    if ("Closed".equalsIgnoreCase(ticket.status) || "Resolved".equalsIgnoreCase(ticket.status)) {
+                        ticket.status = "Open";
+                        ticket.persist();
+                    }
+                }
+            }
+
             if (ticket == null) {
-                return IncomingEmailResult.ignored();
+                ticket = createTicketForIncoming(sender, subject, body);
+                if (ticket == null) {
+                    return IncomingEmailResult.ignored();
+                }
             }
         }
         Message message = new Message();
@@ -192,6 +210,66 @@ private void assignCompanyTams(Ticket ticket) {
         }
     }
 
+    private Ticket findExistingTicketWithSameStackTrace(User sender, List<String> incomingTraces) {
+        if (incomingTraces.isEmpty()) {
+            return null;
+        }
+        Company company = companyForSender(sender);
+        if (company == null) {
+            return null;
+        }
+
+        Set<String> normalizedIncoming = new HashSet<>();
+        for (String trace : incomingTraces) {
+            normalizedIncoming.add(StackTraceExtractor.normalizeStackTrace(trace));
+        }
+
+        List<Message> companyMessages = Message
+                .list("select m from Message m join m.ticket t where t.company = ?1 order by t.id desc", company);
+        for (Message m : companyMessages) {
+            if (m.body != null) {
+                List<String> traces = StackTraceExtractor.extractStackTraces(m.body);
+                for (String trace : traces) {
+                    if (normalizedIncoming.contains(StackTraceExtractor.normalizeStackTrace(trace))) {
+                        return m.ticket;
+                    }
+                }
+            }
+        }
+
+        List<Attachment> companyAttachments = Attachment.list(
+                "select a from Attachment a join a.message m join m.ticket t where t.company = ?1 order by t.id desc",
+                company);
+        for (Attachment a : companyAttachments) {
+            if (a.data != null) {
+                String text = new String(a.data, java.nio.charset.StandardCharsets.UTF_8);
+                List<String> traces = StackTraceExtractor.extractStackTraces(text);
+                for (String trace : traces) {
+                    if (normalizedIncoming.contains(StackTraceExtractor.normalizeStackTrace(trace))) {
+                        return a.message.ticket;
+                    }
+                }
+            }
+        }
+
+        return null;
+    }
+
+    private void escalateTicket(Ticket ticket) {
+        if (ticket == null || ticket.companyEntitlement == null) {
+            return;
+        }
+        CompanyEntitlement escalatedEntitlement = CompanyEntitlement
+                .find("company = ?1 and entitlement = ?2 and supportLevel.name = ?3", ticket.company,
+                        ticket.companyEntitlement.entitlement, "Escalate")
+                .firstResult();
+        if (escalatedEntitlement != null) {
+            ticket.companyEntitlement = escalatedEntitlement;
+            ticket.persist();
+            LOGGER.infof("Ticket '%s' escalated to Escalate level due to duplicate stack trace", ticket.name);
+        }
+    }
+
     public record IncomingEmailResult(boolean processed, String ticketName) {
 
         static IncomingEmailResult processed(String ticketName) {
diff --git a/src/backend/main/java/ai/mnemosyne_systems/service/StackTraceExtractor.java b/src/backend/main/java/ai/mnemosyne_systems/service/StackTraceExtractor.java
new file mode 100644
index 00000000..605254c9
--- /dev/null
+++ b/src/backend/main/java/ai/mnemosyne_systems/service/StackTraceExtractor.java
@@ -0,0 +1,93 @@
+/*
+ * Eclipse Public License - v 2.0
+ *
+ *   THE ACCOMPANYING PROGRAM IS PROVIDED UNDER THE TERMS OF THIS ECLIPSE
+ *   PUBLIC LICENSE ("AGREEMENT"). ANY USE, REPRODUCTION OR DISTRIBUTION
+ *   OF THE PROGRAM CONSTITUTES RECIPIENT'S ACCEPTANCE OF THIS AGREEMENT.
+ */
+
+package ai.mnemosyne_systems.service;
+
+import ai.mnemosyne_systems.model.Attachment;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+
+public class StackTraceExtractor {
+
+    public static List<String> extractStackTraces(String text) {
+        List<String> traces = new ArrayList<>();
+        if (text == null || text.isBlank()) {
+            return traces;
+        }
+        String[] lines = text.split("\\R");
+        int i = 0;
+        while (i < lines.length) {
+            String line = lines[i].trim();
+            if (isFrameLine(line)) {
+                List<String> block = new ArrayList<>();
+                // Look backward for exception/header line
+                String header = null;
+                if (i > 0) {
+                    String prev = lines[i - 1].trim();
+                    if (!isFrameLine(prev) && (prev.contains("Exception") || prev.contains("Error")
+                            || prev.contains("Throwable") || prev.contains("at "))) {
+                        header = prev;
+                    }
+                }
+                if (header != null) {
+                    block.add(header);
+                }
+
+                int frameCount = 0;
+                while (i < lines.length) {
+                    String curr = lines[i].trim();
+                    if (isFrameLine(curr) || curr.startsWith("Caused by:")
+                            || curr.matches("^\\s*\\.\\.\\.\\s+\\d+\\s+more\\s*$")) {
+                        block.add(curr);
+                        if (isFrameLine(curr)) {
+                            frameCount++;
+                        }
+                        i++;
+                    } else {
+                        break;
+                    }
+                }
+                if (frameCount >= 2) {
+                    traces.add(String.join("\n", block));
+                }
+            } else {
+                i++;
+            }
+        }
+        return traces;
+    }
+
+    public static List<String> extractStackTracesFromAttachments(List<Attachment> attachments) {
+        List<String> traces = new ArrayList<>();
+        if (attachments == null) {
+            return traces;
+        }
+        for (Attachment attachment : attachments) {
+            if (attachment.data != null) {
+                String text = new String(attachment.data, StandardCharsets.UTF_8);
+                traces.addAll(extractStackTraces(text));
+            }
+        }
+        return traces;
+    }
+
+    public static String normalizeStackTrace(String trace) {
+        if (trace == null) {
+            return "";
+        }
+        // Remove line numbers like :123) with )
+        String withoutLineNumbers = trace.replaceAll(":\\d+\\)", ")");
+        // Replace all whitespace with a single space to ignore formatting differences
+        return withoutLineNumbers.replaceAll("\\s+", " ").trim();
+    }
+
+    private static boolean isFrameLine(String line) {
+        return line.startsWith("at ") && line.contains("(") && line.contains(")");
+    }
+}
diff --git a/src/backend/test/java/ai/mnemosyne_systems/resource/SupportAccessTest.java b/src/backend/test/java/ai/mnemosyne_systems/resource/SupportAccessTest.java
index 49c6d226..9692f692 100644
--- a/src/backend/test/java/ai/mnemosyne_systems/resource/SupportAccessTest.java
+++ b/src/backend/test/java/ai/mnemosyne_systems/resource/SupportAccessTest.java
@@ -730,6 +730,58 @@ void incomingEmailWithoutTicketSubjectCreatesTicket() {
         Assertions.assertTrue(saved.ticket.name.contains("-"));
     }
 
+    @Test
+    void incomingEmailWithDuplicateStackTraceUpdatesExistingTicketAndEscalates() {
+        mailbox.clear();
+        ensureUser("user", "user@mnemosyne-systems.ai", User.TYPE_USER, "user");
+        Long companyId = ensureCompany("Incoming Deduplication Co");
+        ensureCompanyUsers(companyId, "user@mnemosyne-systems.ai");
+
+        ensureEscalateEntitlementSupport(companyId);
+
+        String stackTrace = "java.lang.NullPointerException: test exception\n"
+                + "    at com.example.TestService.execute(TestService.java:23)\n"
+                + "    at com.example.TestService.run(TestService.java:10)";
+
+        String body1 = "We hit this error:\n" + stackTrace;
+
+        RestAssured.given().contentType("multipart/form-data").multiPart("from", "user@mnemosyne-systems.ai")
+                .multiPart("subject", "Crash report").multiPart("body", body1).post("/mail/incoming").then()
+                .statusCode(200);
+
+        Message saved1 = findMessageByBody(body1);
+        Assertions.assertNotNull(saved1);
+        Ticket ticket = saved1.ticket;
+        Assertions.assertNotNull(ticket);
+
+        Assertions.assertEquals("Normal", ticket.companyEntitlement.supportLevel.name);
+
+        setTicketStatus(ticket.id, "Closed");
+
+        String body2 = "Help, it happened again!\n" + stackTrace;
+        RestAssured.given().contentType("multipart/form-data").multiPart("from", "user@mnemosyne-systems.ai")
+                .multiPart("subject", "Second crash report").multiPart("body", body2).post("/mail/incoming").then()
+                .statusCode(200);
+
+        Message saved2 = findMessageByBody(body2);
+        Assertions.assertNotNull(saved2);
+        Assertions.assertEquals(ticket.id, saved2.ticket.id);
+
+        Ticket refreshed = refreshedTicket(ticket.id);
+        Assertions.assertEquals("Open", refreshed.status);
+        Assertions.assertEquals("Escalate", refreshed.companyEntitlement.supportLevel.name);
+    }
+
+    @Transactional
+    void ensureEscalateEntitlementSupport(Long companyId) {
+        Company company = Company.findById(companyId);
+        Entitlement entitlement = ensureEntitlement("Starter", "Email support");
+        Level normal = ensureLevel("Normal", "Normal response", 1440, "White");
+        Level escalate = ensureLevel("Escalate", "Escalate response", 120, "Yellow");
+        ensureCompanyEntitlement(company, entitlement, normal);
+        ensureCompanyEntitlement(company, entitlement, escalate);
+    }
+
     @Test
     void incomingEmailIgnoresUnknownOrMismatchedFrom() {
         mailbox.clear();
diff --git a/src/backend/test/java/ai/mnemosyne_systems/service/StackTraceExtractorTest.java b/src/backend/test/java/ai/mnemosyne_systems/service/StackTraceExtractorTest.java
new file mode 100644
index 00000000..694b51b9
--- /dev/null
+++ b/src/backend/test/java/ai/mnemosyne_systems/service/StackTraceExtractorTest.java
@@ -0,0 +1,83 @@
+/*
+ * Eclipse Public License - v 2.0
+ *
+ *   THE ACCOMPANYING PROGRAM IS PROVIDED UNDER THE TERMS OF THIS ECLIPSE
+ *   PUBLIC LICENSE ("AGREEMENT"). ANY USE, REPRODUCTION OR DISTRIBUTION
+ *   OF THE PROGRAM CONSTITUTES RECIPIENT'S ACCEPTANCE OF THIS AGREEMENT.
+ */
+
+package ai.mnemosyne_systems.service;
+
+import ai.mnemosyne_systems.model.Attachment;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.List;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class StackTraceExtractorTest {
+
+    @Test
+    public void testExtractStackTracesFromText() {
+        String body = "Hey developer,\n" + "I encountered the following issue in production:\n\n"
+                + "java.lang.NullPointerException: Cannot invoke \"String.trim()\" because \"body\" is null\n"
+                + "    at ai.mnemosyne_systems.service.IncomingEmailService.processIncomingEmail(IncomingEmailService.java:44)\n"
+                + "    at ai.mnemosyne_systems.resource.IncomingEmailResource.process(IncomingEmailResource.java:52)\n"
+                + "\n" + "Please fix this ASAP!";
+
+        List<String> traces = StackTraceExtractor.extractStackTraces(body);
+        Assertions.assertEquals(1, traces.size());
+
+        String trace = traces.get(0);
+        Assertions.assertTrue(trace.contains("java.lang.NullPointerException"));
+        Assertions.assertTrue(trace.contains("processIncomingEmail"));
+        Assertions.assertTrue(trace.contains("process"));
+    }
+
+    @Test
+    public void testExtractStackTracesFromAttachments() {
+        Attachment attachment = new Attachment();
+        attachment.name = "error.log";
+        attachment.mimeType = "text/plain";
+        attachment.data = ("Uncaught exception:\n" + "java.lang.RuntimeException: Something went wrong\n"
+                + "    at ai.mnemosyne_systems.service.SomeService.doWork(SomeService.java:12)\n"
+                + "    at ai.mnemosyne_systems.service.SomeService.start(SomeService.java:8)\n"
+                + "Caused by: java.io.IOException: Disk full\n"
+                + "    at java.base/java.io.FileOutputStream.writeBytes(Native Method)\n" + "    ... 3 more")
+                        .getBytes(StandardCharsets.UTF_8);
+
+        List<String> traces = StackTraceExtractor
+                .extractStackTracesFromAttachments(Collections.singletonList(attachment));
+        Assertions.assertEquals(1, traces.size());
+
+        String trace = traces.get(0);
+        Assertions.assertTrue(trace.contains("java.lang.RuntimeException"));
+        Assertions.assertTrue(trace.contains("doWork"));
+        Assertions.assertTrue(trace.contains("Disk full"));
+    }
+
+    @Test
+    public void testNormalizeStackTrace() {
+        String trace1 = "java.lang.NullPointerException\n"
+                + "    at ai.mnemosyne_systems.service.IncomingEmailService.processIncomingEmail(IncomingEmailService.java:44)\n"
+                + "    at ai.mnemosyne_systems.resource.IncomingEmailResource.process(IncomingEmailResource.java:52)";
+
+        String trace2 = "java.lang.NullPointerException\n"
+                + "  at ai.mnemosyne_systems.service.IncomingEmailService.processIncomingEmail(IncomingEmailService.java:46)\n"
+                + "  at ai.mnemosyne_systems.resource.IncomingEmailResource.process(IncomingEmailResource.java:53)";
+
+        String normalized1 = StackTraceExtractor.normalizeStackTrace(trace1);
+        String normalized2 = StackTraceExtractor.normalizeStackTrace(trace2);
+
+        Assertions.assertEquals(normalized1, normalized2);
+        Assertions.assertFalse(normalized1.contains("44"));
+        Assertions.assertFalse(normalized2.contains("46"));
+    }
+
+    @Test
+    public void testNoStackTrace() {
+        String body = "Hello, I have a question about how to set up SSO on the business plan.";
+        List<String> traces = StackTraceExtractor.extractStackTraces(body);
+        Assertions.assertTrue(traces.isEmpty());
+    }
+}