I cannot receive emails.

I create several email accounts and i have the same problem with all of them, for sending its ok, but for receiving dont work. This is the message that people receive when they try to write me: : 550: 5.1.1 The email account that you tried to reach does not exist. Please try 5.1.1 double-checking the recipient's email address for typos or 5.1.1 unnecessary spaces. Learn more at 5.1.1 https://support.google.com/mail/?p=NoSuchUser a126-v6si2978804itc.142 - gsmtp