January 19, 2020

SPF – The first MUST solution to try You need to create TXT record on your DNS.Change YOUR_HOSTING_IP with your website IP (hosting server):v=spf1 ip4:YOUR_HOSTING_IP include:spf.protection.outlook.com -all See here for more help: https://mxtoolbox.com/c/outboundemailsources?public=Office365 Cpanel Possible solutions: Conclusions Even if one of the above it’s not your case I can say for sure this is not a