Make sure you set up your SPF record. It'll look something like: "v=spf1 a mx include:sendgrid.net ~all" You can check your current one with: host -t txt

Make sure you set up your SPF record. It'll look something like: "v=spf1 a mx include:sendgrid.net ~all" You can check your current one with: host -t txt yourdomain.com Yours will likely differ based on your needs, but you need the include: for SG there. Send an email through SG to a Gmail address and check the full headers. Look for spf=pass and that they're attaching all the DKIM info.