certified mail question

[immihelp]

Hello,

I helped my friend with his N-400 form and he completed everything according to the USCIS guidelines. However, when he sent in his forms and documents to the appropriate service center, he did not send them via certified mail. Is this a major problem? Will it delay the processing of his N-400? What is an appropriate way to check the status of his application -- seeing if his check was cashed, calling the service center's customer service line? Any advice you could offer would be greatly appreciated.

Thank you

[immihelp]

It's ok if he didn't send by certified mail.

Best way to track is to see whether the check was cashed.