Proof of delivery for 3520?

Hello all,

 

I know that 3520 can only be filed through mail. The question is : how do I know that the IRS actually received the form?

-Some suggest that I sent it through certified delivery with signature required on delivered and keep that record as receipt in case IRS lose my form or it get lost during mailing.

-Others said that I filed 4506-T request for transcript of tax return and request 3520 on line 6 and check record of transcript for the current tax year after 1 week or 2  to see if IRS actually receive and record my 3520 in the system. Or is there any other form that can help me request a receipt of 3520 that you can suggest?

 

I know that I should talk to a tax professional; however, there is no tax professional near me that specialize in this work (I even seek out online tax expert, but they all said it is not guaranteed) so here I am asking the community of experts to give some pointers.