Office 365 Configuration Issue?
This one's hard to describe but I'll give it a go.
We use Marketo to send a number of newsletters to internal audiences. Our dedicated IP address is whitelisted, and we've had no internal deliverability issues. Here's what I noticed though: a couple of our newsletters had been getting 70-80% open rates for months and months until July of 2019. At that point open rates dropped in half or worse. Again - only going to internal people. One of our IT resources says that we need to make some config changes to Outlook 365 / Azure (?) in order to solve this problem. He says the emails are being delivered; they're not going to SPAM. He asked that I come up with steps needed to re-onboard Marketo in our new Office 365 environment. Any clues, suggestions?