diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateKeyEmailFragment.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateKeyEmailFragment.java
index 2e8a1f370..7e2e1c31c 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateKeyEmailFragment.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateKeyEmailFragment.java
@@ -39,6 +39,7 @@ import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.ui.CreateKeyActivity.FragAction;
 import org.sufficientlysecure.keychain.ui.dialog.AddEmailDialogFragment;
 import org.sufficientlysecure.keychain.ui.dialog.SetPassphraseDialogFragment;
+import org.sufficientlysecure.keychain.ui.util.Notify;
 import org.sufficientlysecure.keychain.ui.widget.EmailEditText;
 
 import java.util.ArrayList;
@@ -122,16 +123,22 @@ public class CreateKeyEmailFragment extends Fragment {
         mEmailsRecyclerView.setItemAnimator(new DefaultItemAnimator());
 
         // initial values
-        mAdditionalEmailModels = new ArrayList<>();
-        if (mCreateKeyActivity.mAdditionalEmails != null) {
-            setAdditionalEmails(mCreateKeyActivity.mAdditionalEmails);
-        }
-        mEmailAdapter = new EmailAdapter(mAdditionalEmailModels, new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                addEmail();
+        if (mAdditionalEmailModels == null) {
+            mAdditionalEmailModels = new ArrayList<>();
+            if (mCreateKeyActivity.mAdditionalEmails != null) {
+                setAdditionalEmails(mCreateKeyActivity.mAdditionalEmails);
             }
-        });
+        }
+
+        if (mEmailAdapter == null) {
+            mEmailAdapter = new EmailAdapter(mAdditionalEmailModels, new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    addEmail();
+                }
+            });
+        }
+
         mEmailsRecyclerView.setAdapter(mEmailAdapter);
 
         return view;
@@ -144,10 +151,27 @@ public class CreateKeyEmailFragment extends Fragment {
                 if (message.what == SetPassphraseDialogFragment.MESSAGE_OKAY) {
                     Bundle data = message.getData();
 
+                    String email = data.getString(AddEmailDialogFragment.MESSAGE_DATA_EMAIL);
+
+                    if (email.length() > 0 && mEmailEdit.getText().length() > 0 &&
+                            email.equals(mEmailEdit.getText().toString())) {
+                        Notify.create(getActivity(),
+                                getString(R.string.create_key_email_already_exists_text),
+                                Notify.LENGTH_LONG, Notify.Style.ERROR).show();
+                        return;
+                    }
+                    //check for duplicated emails inside the adapter
+                    for (EmailAdapter.ViewModel model : mAdditionalEmailModels) {
+                        if (email.equals(model.email)) {
+                            Notify.create(getActivity(),
+                                    getString(R.string.create_key_email_already_exists_text),
+                                    Notify.LENGTH_LONG, Notify.Style.ERROR).show();
+                            return;
+                        }
+                    }
+
                     // add new user id
-                    mEmailAdapter.add(
-                            data.getString(AddEmailDialogFragment.MESSAGE_DATA_EMAIL)
-                    );
+                    mEmailAdapter.add(email);
                 }
             }
         };
diff --git a/OpenKeychain/src/main/res/values/strings.xml b/OpenKeychain/src/main/res/values/strings.xml
index 8c4fe2a33..6ee30887b 100644
--- a/OpenKeychain/src/main/res/values/strings.xml
+++ b/OpenKeychain/src/main/res/values/strings.xml
@@ -629,6 +629,7 @@
     <string name="create_key_edit">"Change key configuration"</string>
     <string name="create_key_add_email">"Add email address"</string>
     <string name="create_key_add_email_text">"Additional email addresses are also associated to this key and can be used for secure communication."</string>
+    <string name="create_key_email_already_exists_text">"Email has already been added"</string>
 
     <!-- View key -->
     <string name="view_key_revoked">"Revoked: Key must not be used anymore!"</string>