Your SendGrid account may not yet be configured with DKIM signing and correct DNS records (DKIM, and CNAME). When properly set up, it should not be necessary to have include:sendgrid.net in your SPF, although you may want to check with SendGrid about that. (Same with MailChimp, probably.)
So you need to identify and talk to the person(s) using SendGrid in your organisation. They’ll be wondering why 50 % of their stuff currently ends up in spam folders.
