All of our customers who have hotmail/live/msn/outlook emails account have reported as not receiving the email neither in their inbox nor in their junk/spam folder, moreover some of them reporting that always receiving the mails in junk folder. We are using SendGrid to distribute the emails. SendGrid says the emails were delivered. The emails have text with an invitation link, no image or multimedia in it.
We do not know what is going on with hotmail/live/msn/outlook. Is our dedicate IP blacklist or something else? Please suggest us.