Improve the handling of E-Mails that are greylisted
We have massive issues with E-Mails getting greylisted when sent via Exchange Online Protection. We have about 700-1.000 E-Mails daily with Status "pending" in EOP. These E-Mails eventually get delivered, but the delay normally is between 1 or 2 days, which isn't acceptable. The recommendation from MS to contact all recipients to adjust their filters, is not practicable. We have thousands of customers which were used to receive e.g. pricing Information, offers and invoices in an acceptable time frame which isn't the case anymore since we switched to EOP.
I have that problem too.
It should be possible, that you configure your servers in a way, that each email is sent from the same server (IP-address), when it is not delivered the first time.
It is necessary, that the sending IP-adress stays the same for each single email.
Recommendation: Limit the number of sending IPs for a particular message to increase the chance that messages pass the geylistfilter.