My commit in a jiffy :

1) Rename `signinSuccessful` to `connectionSuccessful` - because its `setValue` method only marks successful connection creation attempts and not signin attempts.
 2) Set initial connections added through `accountRespository.insertAccount(..)` as invalid, they can later be marked valid once we are able to login successfully.
 3) Add a `isValid` field in `RoomAccountModel`, along with it's respective getters and setters.
 4) Add `isValid` getters and setters to `AccountModel` interface.

What problem I currently am facing is,
 Just like `accountRepository.insertAccount(..)`, I tried `accountRepository.updateAccount(..)` which didn't seem to work.
 I interpreted this by observing the accountmodel status in `startUp`, after restarting the app field `isValid = invalid` should have turned to `isValid = valid` which was not expected.
Please let me know what you think.

app/src/main/java/org/mercury_im/messenger/ui/login/LoginActivity.java

@@ -114,7 +114,7 @@ public class LoginActivity extends AppCompatActivity implements TextView.OnEdito
             mPasswordView.setError(errorMessage);
         });
 
-        viewModel.getSigninSuccessful().observe(this, aBoolean -> {
+        viewModel.getConnectionSuccessful().observe(this, aBoolean -> {
             if (Boolean.TRUE.equals(aBoolean)) {
                 finish();
             }

app/src/main/java/org/mercury_im/messenger/ui/login/LoginViewModel.java

@@ -41,7 +41,7 @@ public class LoginViewModel extends ViewModel {
 
     private MutableLiveData<AccountModel> account = new MutableLiveData<>();
 
-    private MutableLiveData<Boolean> signinSuccessful = new MutableLiveData<>();
+    private MutableLiveData<Boolean> connectionSuccessful = new MutableLiveData<>();
 
     public LoginViewModel() {
         super();
@@ -49,8 +49,8 @@ public class LoginViewModel extends ViewModel {
         init(accountRepository.newAccountModel());
     }
 
-    public LiveData<Boolean> getSigninSuccessful() {
-        return signinSuccessful;
+    public LiveData<Boolean> getConnectionSuccessful() {
+        return connectionSuccessful;
     }
 
     public enum JidError {
@@ -136,6 +136,7 @@ public class LoginViewModel extends ViewModel {
             accountModel.setEnabled(true);
             accountModel.setJid(bareJid);
             accountModel.setPassword(password);
+            accountModel.setIsValid("invalid");
             Single<Long> id = accountRepository.insertAccount(accountModel);
             id.subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
@@ -145,7 +146,7 @@ public class LoginViewModel extends ViewModel {
                             accountModel.setId(aLong);
                             Log.d(MercuryImApplication.TAG, "LoginActivity.loginDetailsEntered: Account " + aLong + " inserted.");
                             connectionCenter.createConnection(accountModel);
-                            signinSuccessful.setValue(true);
+                            connectionSuccessful.setValue(true);
                         }
 
                         @Override

core/src/main/java/org/mercury_im/messenger/core/centers/ConnectionCenter.java

@@ -126,8 +126,16 @@ public class ConnectionCenter {
                                 continue;
                             }
                             LOGGER.log(Level.INFO, "Connecting connection " + account.getId() + " (" + account.getJid().toString() + ")");
-                            connection.connect();
-                            LOGGER.log(Level.INFO, "Connected!");
+                            try {
+                                connection.connect();
+                                account.setIsValid("valid");
+                                accountRepository.updateAccount(account);
+                                LOGGER.log(Level.INFO, "Connected!");
+                            }
+                            catch ( SmackException e) {
+                                Logger.getAnonymousLogger().log(Level.WARNING,"Trouble logging in");
+                                e.printStackTrace();
+                            }
                         } else {
                             if (!connection.getConnection().isConnected()) {
                                 continue;

persistence-room/src/main/java/org/mercury_im/messenger/persistence/room/model/RoomAccountModel.java

@@ -25,6 +25,7 @@ public class RoomAccountModel extends AbstractAccountModel {
     public static final String KEY_PASSWORD = "password";
     public static final String KEY_ENABLED = "enabled";
     public static final String KEY_STATE = "state";
+    public static final String KEY_ISVALID = "isValid";
 
     @PrimaryKey(autoGenerate = true)
     @ColumnInfo(name = KEY_ID)
@@ -43,6 +44,9 @@ public class RoomAccountModel extends AbstractAccountModel {
     @ColumnInfo(name = KEY_STATE)
     private String state;
 
+    @ColumnInfo(name = KEY_ISVALID)
+    private String isValid;
+
     @Override
     public long getId() {
         return id;
@@ -93,6 +97,17 @@ public class RoomAccountModel extends AbstractAccountModel {
         this.state = state;
     }
 
+    @Override
+    public String getIsValid(){
+        return isValid;
+    }
+
+    @Override
+    public void setIsValid(String isValid) {
+        this.isValid = isValid;
+    }
+
+
     @Override
     @NonNull
     public String toString() {
@@ -101,7 +116,8 @@ public class RoomAccountModel extends AbstractAccountModel {
                 KEY_JID + ": " + (getJid() != null ? getJid().toString() : "null") + ", " +
                 KEY_PASSWORD + ": " + getPassword() + ", " +
                 KEY_ENABLED + ": " + getEnabled() + ", " +
-                KEY_STATE + ": " +getState() +
+                KEY_STATE + ": " + getState() + ", " +
+                KEY_ISVALID + ": " + getIsValid() +
                 "]";
     }
 }

persistence/src/main/java/org/mercury_im/messenger/persistence/model/AccountModel.java

@@ -71,4 +71,13 @@ public interface AccountModel {
     String getState();
 
     void setState(String state);
+
+    /**
+     * Set wheather the jid-password combination works or not
+     *
+     * @return valid / invalid
+     */
+    String getIsValid();
+
+    void setIsValid(String validity);
 }