PP H1B Extn beyond 6 years, got RFE on Mar10, Suspension of PP from Apr 3

[CGH]

Hello,

My H1b Extn beyond 6 years was filed on Mar3-2017 in PP based on approved I-140. 

I got RFE on Mar10-2017, the USCIS website says RFE notice has been mailed. 

Considering the fact that PP is suspended from Apr3, will the processing of my H1B extn after the RFE response has been sent--- be under Premium or Regular? The attorney is based in Canada and I am not sure how many days the mail will take to reach them and how fast they will respond to RFE. 

Assuming the response to RFE reach USCIS after Apr3--will my case still be under PP or regular?

Any idea which mail service does USCIS use to send RFE notice and how many days it take?

IS it possible to request the RFE via E-Mail or FaX ( checked with attorney they havent received Email or fax so far).

Looking forward for your response.

Thanks,

CGH