Respond to CO in mail

#1
Hi there, Do we need to respond to CO in mail also once the documents they requested are uploaded or just pressing the "information provided" button would be sufficient. Will sending a mail make any difference? Note: I have doubt because in GSM allocated mail, they requested to respond using the CO details provided. TIA.
#2
Reply using immi account is enough
#3
I did write an email after pressing IP. There is no harm in writing an email.
#4
Yes we need to reply as they mention in their email, that you have to reply in writing . So better send am email addressing the CO name and your application ID , ref no.
#5
Yes we need to reply as they mention in their email, that you have to reply in writing . So better send am email addressing the CO name and your application ID , ref no.