Hello,
I'm dealling with the error:
PU1APC01FT023.mail.protection.outlook.com
Remote Server returned '550 5.7.1 Service unavailable, Client host [x.x.x.x] blocked using Spamhaus. To request removal from this list see https://www.spamhaus.org/query/ip/[x.x.x.x] (AS16012611)'
I do REMOVE the ip from all the SPAMHAUS lists for days, BUT mail.protection.outlook.com KEEP reject my email. What should I do now?