Update 03/03/2021 15:50 PM 11 hrs
ExchangeDefender is currently having issues processing mail from extended / vanity top level domains (ex: .aero, .xxx, .moscow). Senders are receiving an error:
5.5.0 5.5.3 Your mail provider suffers of poor reputation. Please contact them ID8841086
Messages from these servers and addresses will start processing again shortly.
Background: Extended tlds are a constant source of malware and attacks on our network. The provider that we are receiving registration data from (to see if the domain is newly registered and thus banned vs. reputation checking) is providing bad data, causing the rejections. We are currently working around it.