diff --git a/server/src/com/mirth/connect/server/userutil/DestinationSet.java b/server/src/com/mirth/connect/server/userutil/DestinationSet.java
index 6b19594705..738d4c350f 100644
--- a/server/src/com/mirth/connect/server/userutil/DestinationSet.java
+++ b/server/src/com/mirth/connect/server/userutil/DestinationSet.java
@@ -101,9 +101,9 @@ public boolean removeAllExcept(Object metaDataIdOrConnectorName) {
         if (metaDataIds != null) {
             Integer metaDataId = convertToMetaDataId(metaDataIdOrConnectorName);
 
-            if (metaDataId != null) {
-                return metaDataIds.retainAll(Collections.singleton(metaDataId));
-            }
+            Set<Integer> set = (metaDataId != null) ? Collections.singleton(metaDataId) : Collections.emptySet();
+
+            return metaDataIds.retainAll(set);
         }
 
         return false;
@@ -165,4 +165,4 @@ private Integer convertToMetaDataId(Object metaDataIdOrConnectorName) {
 
         return null;
     }
-}
\ No newline at end of file
+}
diff --git a/server/test/com/mirth/connect/server/userutil/DestinationSetTest.java b/server/test/com/mirth/connect/server/userutil/DestinationSetTest.java
new file mode 100644
index 0000000000..25f390bf3d
--- /dev/null
+++ b/server/test/com/mirth/connect/server/userutil/DestinationSetTest.java
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: MPL-2.0
+// SPDX-FileCopyrightText: 2025 Richard Ogin
+// SPDX-FileCopyrightText: 2025 Tony Germano <tony@germano.name>
+
+package com.mirth.connect.server.userutil;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Test;
+
+import com.mirth.connect.donkey.model.message.ConnectorMessage;
+import com.mirth.connect.donkey.server.Constants;
+import com.mirth.connect.userutil.ImmutableConnectorMessage;
+
+public class DestinationSetTest {
+    private Set<Integer> createMetadataIds() {
+        Set<Integer> metaDataIds = new HashSet<>();
+        metaDataIds.add(1);
+        metaDataIds.add(3);
+        metaDataIds.add(5);
+        metaDataIds.add(7);
+        metaDataIds.add(9);
+
+        return metaDataIds;
+    }
+
+    private Map<String, Integer> createDestinationIdMap() {
+        Map<String, Integer> destinationIdMap = new HashMap<>();
+        destinationIdMap.put("One", 1);
+        destinationIdMap.put("Three", 3);
+        destinationIdMap.put("Five", 5);
+        destinationIdMap.put("Seven", 7);
+        destinationIdMap.put("Nine", 9);
+
+        return destinationIdMap;
+    }
+
+    private ImmutableConnectorMessage createMessage(Map<String, Integer> destinationIdMap, Set<Integer> metadataIds) {
+        ConnectorMessage cm = new ConnectorMessage();
+
+        if (metadataIds != null) {
+            cm.getSourceMap().put(Constants.DESTINATION_SET_KEY, metadataIds);
+        }
+
+        if (destinationIdMap != null) {
+            return new ImmutableConnectorMessage(cm, true, destinationIdMap);
+        } else {
+            return new ImmutableConnectorMessage(cm, true);
+        }
+    }
+
+    // --- Tests for remove(Object) ---
+    @Test
+    public void test_removeObject_withSourceMap_removeForMatchingMetadataId() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.remove(3));
+        assertFalse(metaDataIds.contains(3));
+        assertTrue(metaDataIds.size() == 4);
+    }
+
+    @Test
+    public void test_removeObject_withSourceMap_removeForMatchingConnectorName() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.remove("Five"));
+        assertFalse(metaDataIds.contains(5));
+        assertTrue(metaDataIds.size() == 4);
+    }
+
+    @Test
+    public void test_removeObject_withSourceMap_noRemovalForNonExistentName() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertFalse(destinationSet.remove("I_DONT_EXIST"));
+        assertTrue(metaDataIds.size() == 5);
+    }
+
+    @Test
+    public void test_removeObject_noSourceMap_noRemoval() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+        assertFalse(destinationSet.remove(3));
+    }
+
+    // --- Tests for remove(Collection) ---
+    @Test
+    public void test_removeCollection_withSourceMap_removeForMatchingItems() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        Collection<Object> toRemove = Arrays.asList(1, "Three", 99); // "99" does not exist
+        assertTrue(destinationSet.remove(toRemove));
+        assertFalse(metaDataIds.contains(1));
+        assertFalse(metaDataIds.contains(3));
+        assertTrue(metaDataIds.size() == 3);
+    }
+    
+    @Test
+    public void test_removeCollection_withSourceMap_noRemovalForNonExistentItems() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        Collection<Object> toRemove = Arrays.asList(100, "OneHundred");
+        assertFalse(destinationSet.remove(toRemove));
+        assertTrue(metaDataIds.size() == 5);
+    }
+
+    @Test
+    public void test_removeCollection_noSourceMap_noRemoval() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+        assertFalse(destinationSet.remove(Arrays.asList(1, "Three")));
+    }
+
+    // --- Tests for removeAll() ---
+    @Test
+    public void test_removeAll_withSourceMap_removesAll() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAll());
+        assertTrue(metaDataIds.isEmpty());
+    }
+    
+    @Test
+    public void test_removeAll_withSourceMap_returnsFalseWhenAlreadyEmpty() throws Exception {
+        Set<Integer> metaDataIds = new HashSet<>();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertFalse(destinationSet.removeAll());
+    }
+
+    @Test
+    public void test_removeAll_noSourceMap_noRemoval() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+        assertFalse(destinationSet.removeAll());
+    }
+
+    // --- Tests for removeAllExcept(Collection) ---
+    @Test
+    public void test_removeAllExceptCollection_withSourceMap_retainsMatchingItems() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        Collection<Object> toRetain = Arrays.asList(1, "Five", 99); // "99" does not exist
+        assertTrue(destinationSet.removeAllExcept(toRetain));
+        assertTrue(metaDataIds.size() == 2);
+        assertTrue(metaDataIds.contains(1));
+        assertTrue(metaDataIds.contains(5));
+    }
+
+    @Test
+    public void test_removeAllExceptCollection_withSourceMap_removesAllForNonExistentItems() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        Collection<Object> toRetain = Arrays.asList(100, "OneHundred");
+        assertTrue(destinationSet.removeAllExcept(toRetain));
+        assertTrue(metaDataIds.isEmpty());
+    }
+
+    @Test
+    public void test_removeAllExceptCollection_noSourceMap_noRemoval() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+        assertFalse(destinationSet.removeAllExcept(Arrays.asList(1, "Five")));
+    }
+    
+    // --- Tests for removeAllExcept(Object) ---
+    @Test
+    public void test_removeAllExceptObject_withSourceMap_removeAllForMetadataIdWhichDoesNotExist() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAllExcept("I_DONT_EXIST"));
+        assertTrue(metaDataIds.isEmpty());
+    }
+
+    @Test
+    public void test_removeAllExceptObject_withSourceMap_removeForMatchingMetadataId() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAllExcept(3));
+        assertTrue(metaDataIds.size() == 1);
+    }
+
+    @Test
+    public void test_removeAllExceptObject_withSourceMap_removeForMatchingConnectorName() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAllExcept("Seven"));
+        assertTrue(metaDataIds.size() == 1);
+    }
+
+    @Test
+    public void test_removeAllExceptObject_noSourceMap_noRemovalForMetadataIdWhichDoesNotExist() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+
+        assertFalse(destinationSet.removeAllExcept("I_DONT_EXIST"));
+    }
+
+    @Test
+    public void test_removeAllExceptObject_noSourceMap_noRemovalForMatchingMetadataId() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+
+        assertFalse(destinationSet.removeAllExcept(3));
+    }
+
+    @Test
+    public void test_removeAllExceptObject_noSourceMap_noRemovalForMatchingConnectorName() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+
+        assertFalse(destinationSet.removeAllExcept("Seven"));
+    }
+}