Hi,
We are getting the same problem with the emails from almost all our suppliers.
This is the failmessage;
"JunkMail rejected - mail-vi1eur04on2113.outbound.protection.outlook.com (EUR04-VI1-obe.outbound.protection.outlook.com) [40.107.8.113]:13093 is in an RBL: Blocked - see https://www.spamcop.net/bl.shtml?40.107.8.113"
Almost all the ip adresses which begins with 40.107.XXX.XXX ends up in Junk mail.
This should be fixed ASAP.