When trying to setup Apple Mail on my parents iMac with an older OSX (not sure exacty) I cannot connect to the blizzard SMTP server using authentication. After some troubeshooting I noticed the error in the diagnostic logs: " 550 HELO is an IP address".
Do you have any idea how to solve this. Setting mail on my parents iPad works fine. TY!
It sounds like your iMac is not authenticating over SMTP, but rather just trying to open relay through the server without auth. Make sure to enable SMTP auth and if the OS X version is old and can’t be updated, make sure to not use SSL either as it probably doesn’t support connections to an up to date secure server (and that may still fail, because old Apple Mail versions are known to just ignore your instruction on that, so I’m told).
Next time I am there I will check again. I did try several configurations and I am not sure what I left with 