Send Mail not working in Laravel 5.1

I have created one demo for sending mail. I am sending mail in contact page it is working. But When I use dynamic email for TO, then it is not working.

Not Working

Mail::send('emails.otp_mail_format',['otp'=>'123456'], function($message){ $message->from('no-reply@example.com'); $message->to($uEmailAddress)->subject('Account Verification'); });

But Working below code

Mail::send('emails.otp_mail_format',['otp'=>'123456'], function($message){ $message->from('no-reply@example.com'); $message->to('kanu@example.come')->subject('Account Verification'); });

via Chebli Mohamed