Beginning a couple of weeks ago, there's seems to be a new feature for Office 365 Exchange Online that now collects all messages that appear as spam (per the company settings, I suppose) and sends them all to quarantine. Every three days or so, the recipient will receive an email like the one below to review those messages (or just ignore them):
I'm wondering what the impact this is having on those of us Marketo customers that send emails to our B2B audiences that use Exchange Online. Is this further going to make email an ineffective tactic for us (given the existing issues around spam bots creating false-positives on opens/clicks)? In the meantime, I'm going to get with our Exchange/deliverability team to see if they can offer more insight around this.