It appears as though our server has been blocked from sending emails to email accounts that use office365's MTAs.
We run campaigns that send 100's of emails out in a go (to subscribed users), this hasn't been a problem in the past but on Sunday they started becoming blocked.
Does anyone know of a way to get this whitelisted as it's having quite an impact on our business?
I've tried the outlook.com whitelist but they replied saying we weren't blacklisted so I assume that's the wrong one?
Again, these emails are not spam, but promo emails sent to subscribed customers... I hate spam too believe me!