No need to submit any sort of response to the mails sent by the ITD as they are reminding all the people to submit Form 61A if they receive cash. I think, the ITD is sending the mails because this is the first time.
All my known profesionals have started filing the SFT Preliminary Response by Selecting SFT 013 as "NO" and submitted it. And did not file any NIL Return Form 61A.
Accordingly to them just process the Manage ITDREIN , since it can be generated without DSC and without adding any Authorised Person.