I agree with Ghaleb – I don't think there is any connection between ARCHICAD and macOS Mail. The structure of macOS also makes that very unlikely - you would have to be doing something really unprofessional to damage other applications on Installation.
It's more likely to be coincidence, but based on a pre-existing problem that only became apparent when you installed ARCHICAD. This can happen when (for example) the directory structure is corrupted, such that drive storage already used for files have been mistakenly marked as unused. If those blocks are written to during an installation, the existing files will be seriously damaged. It will appear as if the new installation caused the problem, when in fact the problem was already there. And if the file structure is corrupted, it will continue to cause damage the longer you work with it, i.e. it won't fix itself.
Did Apple support guide you through the process of rebooting in Recovery Mode and then running a full disk check with Disk Utility?
Ralph Wessel BArch
Software Engineer Speckle Systems