Here is some details about autosupport requirements.
https://library.netapp.com/ecmdocs/ECMP1636037/html/GUID-46433D3E-7EB3-4C17-B097-1380FC0FB55D.html
I'll strongly recommend you using HTTPS, which enable Autosupport OnDemand.
SMTP settings should be is based on your mail server reqirements and you have to meet that.
in some case from address have to have to be a valid email address in the server (not just hostname@domainname)
and you can use the following command to rest the mail delivery to netapp as well as your client's mailbox
::> system autosupport invoke -node * -message test -type test
If you use HTTPS to deliver the mail to NetApp and SMTP to Storage Admin's mailboxes..
both status will report in "sutosupport history show" command.
Robin.