EmailReports of third party mail programs not sending to outlook.com, msn.com, gmail.com or yahoo.com
Our Email team is investigating reports of third party mail programs (specifically Outlook) not successfully sending to outlook.com, msn.com, gmail.com or yahoo.com. This is due to certain third party IP reputation blacklisting.
Recipients can safelist your sending domain in their email client to allow delivery.
Or senders may email through webmail (login at email.firespring.com) to allow delivery as this goes through a different IP range.