Ok I haven’t ever seen Hmail server before and it’s not one of the supported eM Client mail servers.
eM Client Compatibility
eM Client is enterprise-grade software compatible with all major platforms. We fully support these systems.
https://emclient.com/email-services
So suggest to contact Hmail server support for assistance as to this issue.
There maybe someone otherwise on this free forum who has run that mail server before that can help you. Sry I cannot help with that.
If you are a current paid eM Client Pro or Enterprise customer you can contact support via the Pro / Enterprise page and lodge a VIP ticket where they may be able to assist you further.