We have spun up a brand new domain at my company. We are sending legitimate emails that are being quarantined (not blocked) by different exchange online protection domains in office 365. We have run our emails through various tests (spf checks, dnsbl checks, etc) and they come back completely clean. We've reviewed the received headers of various email messages sent to our own personal outlook.com accounts and the Forefront antispam SCL's are set to zero.....however Office365 seems to be the only place where this is happening.
Do we have any recourse other than to tell each of these vendors/partners to add us to their whitelist? That's really the last thing we'd like to do.
Ideas? Is there a place I can open up a ticket with Office365 to gain insight as to why this is happening. I'm not so sure that a handful of these vendors may have the insight to tell me why the message is getting quarantined. Again, this is a brand new domain.