I use Sendgrid for SMTP.
It works for all top level sites.
The problem arises on multisite. It does work on the current_root_domain. However, all of the subsites (subdomains) send the emails to the spam box on gmail.
I have added the SPF record for sendgrid on all of the subdomains.
I've tried setting the "FROM" email in gravity forms to the current_root_domain, but it still goes to spam.
Thanks in advance!