Hey,
While switching to Mac, I had the same problem. MSG files are compatible only with the Windows platform, and Mac Contacts won’t recognize them. What I did was very efficient: I used the TrustVare MSG to VCF Converter, which created perfect VCF files that were immediately imported by Mac.
Here is what made it perfect for Mac:
Exact conversion from MSG to vCard
A large number of files can be converted at the same time without any loss of data.
Supports all fields like notes, company info, addresses, and images
Output is error-free and can be opened in macOS Contacts
Extremely simple to use
If you are seeking trustworthy outcomes, then this MSG to VCF Converter would be a great choice for you, a Mac user.