You evidently misunderstand the nature of the Apple Support Communities. We are not, and do not represent, Apple in any way at all. In posting here you are not addressing Apple. As such, any complaints that you outline here will fall upon deaf ears.
Nobody here has any idea about what you may, or may not, have discussed with Apple Support - that is entirely between you and the Support Team(s) with which you have had prior conversation.
The vast majority of active contributors that you find here are all end-users, just like you. Where we can, contributors provide technical help, advice and guidance in resolving technical issues with Apple products. We all participate here on a voluntary basis. We are neither paid nor receive compensatory reward for our contributions.
Apple’s participation here is principally limited to “moderating” content - ensuring that its Terms or Use (and expected standards of communication between participants) are maintained.
Now, to your issue...
Encrypted email is not just one standard - there are many. You need to understand your Security Target, the type of email encryption that you require, and when it must be used. Nobody here can tell you what you need to achieve in order to meet your own business needs or the requirements of those with whom you interact. As you are clearly discovering, setup and use of “secure email” is not trivial.
In absence of detailed information as to what you are attempting to achieve, by way of setting-up “secure email”, I might presume that you may be attempting to configure S/MIME. To do so, key elements of setup are the generation and signing of required Security Certificates from your Corporate systems - and to install them on your devices; if you don’t have the necessary knowledge or facilities to generate the necessary security certificates, you’re already going have considerable difficulties.
Here is some general information about S/MIME and its configuration with iOS/iPadOS devices:
Use S/MIME to send encrypted messages in an Exchange environment in iOS – Apple Support
https://www.ssl.com/how-to/ios-smime-email-installation/
https://techcommunity.microsoft.com/t5/intune-customer-success/s-mime-functionality-available-in-outlook-for-ios-testflight/ba-p/734885
A potential alternative to the complexities of S/MIME is to consider use of suitable Mail App that meets the requirements of your Security Target. There are many potential choices, ranging from PGP to proprietary solutions. The use of an App can, often, greatly simplify the configuration overhead in setting-up a secure email solution. There are, however, some caveats; you need to understand your needs - and ensure that the selected solution meets the necessary requirements.
If, again, you lack the necessary technical expertise, you might choose a commercial solution that has verifiable (and independent) certification in meeting the compliance requirements that you need. Again, there are many potential solutions that you may need to research (or employ/engage appropriate security and compliance consultancy) before committing to a solution.
One potential proprietary solution that may meet your compliance requirements, that also avoids much of the technical setup and system administration, is Virtru:
https://www.virtru.com/
Virtru is a Commercial product/platform. As with the majority of Commercial software, it has a cost - but for your business needs, you will understand that financial outlay is to be expected. You will note that amongst its many compliance credentials is HIPAA.
Whilst not being able to provide a direct solution to your needs, I hope this insight and guidance goes some distance in leading you in the right direction. I sincerely hope that my one-hour contribution to your problem proves to be helpful to you.
