For H4 petition, can I do e-file?
-Yes.
I checked the list which you recommended to me. Should I convert all the documents into PDF file and upload them?
-No. You still need to send all the support documents by mail after you e-file the I-539. Just print the e-filed confirmation receipt and send all the document to the address showing in the e-filed receipt. Enclose/send the efiled receipt with the support documents (put it on the top).
See this website:
Do I get the confirmation of reception from USCIS immediately right after I finish document transfering online?
-Yes.
If that is true, is it considered to be "received by USCIS"?
-Yes.
I do hear that some people like to do certified-mail. Which way is better (in terms of timing)?
Thanks a lot!