Run the EXE installer and then disable the SmarterMail IIS server in Windows services.
There used to be an option to do a "manual" installation, but, with the requirement of .NET 4.5 and Windows C++ Redistributables (both 32 and 64 bit) that option is no longer available.
So, the best option is now to run the full installer, configure your IIS, and then disable the SmarterMail webserver, via the Windows server services.
The only issue you will encounter is when you update with major version updates when you have to do a complete uninstall of the old version, reboot the server, and then install the new version.
When doing minor version upgrades, be certain to STOP the SmarterMail service, STOP IIS, and then do the minor version upgrade. The SmarterMail service will auto-restart as the minor version upgrade is installed and you will only have to restart the IIS services.
While I probably don't have to tell you this, based on the fact that you referenced A2814, but you should make certain you have disabled SSL 1.0, SSL 2.0, and SSL 3.0 and updated both the CIPHERS and keys to enable TLS 1.1 and TLS 1.2.
You might want to enable TLS 1.0, but, if the A2814 protocol mandates that it's disabled, you will have to disable it. Disabling TLS 1.0 will also disable all Android devices with Android 4.4 and below.
I have a knowledge base article, along with some detailed instructions, and the information to construct the .REG merge files regarding the CIPHERS and SECURITY PROVIDERS at:
Phone: (224) 444-0169
E-Mail and DNS Security Specialist
Network Security Specialist
Customer Service Portal: https://portal.chicagonettech.com
Security Blog: http://networkbastion.blogspot.com/
Web and E-Mail Hosting, E-Mail Security and Consulting