when I try make preview for email in the email templates give me error

when I try send email from site using email templates I insert my email to send to it and add preview give me this error

Internal server error with id B073C564-3A18-06C4-FF48-5CC02A65A800

and then I try in android
here is the code:

BodyParts bp;

@Override
protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_donor_data);


	Backendless.initApp(this, "E5C780D4-B2FB-1170-FF1F-0551BEDECE00",
			"3C28C065-BAB9-8EC6-FF54-AA6EE07B2700", "v1");

	bp= new BodyParts("hi", "tests");
	Backendless.Messaging.sendEmail("hello", bp, "geo.aaar@hotmail.com",new AsyncCallback() {


		@Override
		public void handleFault(BackendlessFault arg0) {
			// TODO Auto-generated method stub
			Toast.makeText(getApplicationContext(), arg0.toString(), Toast.LENGTH_LONG).show();
	Log.e("back_error", arg0.toString());
		}


		@Override
		public void handleResponse(Object arg0) {
			// TODO Auto-generated method stub
			
		}
	});

and give me this error

BackendlessFault{ code: ‘Server.Processing’, message: 'exception during method invocation

Did you modify email settings for your app? It is done in Manage > App Settings > Email Settings.

It is described in the following article (see the bottom part):
https://backendless.com/feature-34-sending-email-from-your-mobile-browser-or-desktop-app/

Regards,
Mark

thanks a lot for reply

I should change the userId to my registeration email
I use my email which I make register by it and make password of my register
and when I make test it give me
Username and Password not accepted

thanks a lot for reply
when I change the userId to the email I use to login in backendless
and the password which I using in backendless
it give me when I click in test Username and Password not accepted

Hi, Ahmed,

The password should be the one you use to login into your email account.

Not just the password, but the email address must be the one you use to login into your email. Backendless will use your userid(email) and password to send out messages.

thanks for reply

my email tell me that there are PCtry to enter my email from Ashburn, Virginia USA and so I change my password to new one
can this the problem
I use the freelancer.kush@gmail.com which is the email of the my register in Backendless
and I enter the new password of the email
and when I click in test it still give me Username and Password not accepted

The machine which tried to use your account is a Backendless computer. When you enter userid and password, we use it to send email any time Backendless sends email in YOUR application. You will need to grant permission to that computer in Google/gmail - they provide instructions for that.

thanks the test is accepted now

thanks for help and Patience in reply

hello I am sorry for that

but the problem happen again the gmail is close enter to the account and enforce me to change the password
how can I add your pc as user or how to disable this feature in gmail
and thanks a lot