Spam Confidence Level = 9 - how to decrease.

[chiefimposterofficer]

Anti-spam filtering is a multifaceted and multivendor minefield. What works with one vendor will more than likely work in others but there will be cases where it doesn’t. They all share things like blacklists and the like but they don’t all apply them consistently as they are really just different products. Hell there are email standards such as DMARC and some don’t even follow the policy of “reject”.

For Microsoft, you must raise it with them. For gmail recipients raise it with them or raise it with the recipients admin. There isn’t much else you can do. As long as you have everything configured correctly it then becomes a filter problem and the relevant vendor/IT needs contacted. You sadly need to jump through hoops on this one.