I'm talking about two independent computers. My daughter is working with OL 2007 under Win7, while I am working with OL for Mac 2011 under Yosemite.

The Win7 system uses (for all practical purposes) a single .pst file, while the Mac system uses a multiple-file structure. As I see it, this means that even a minor change under the Win7 system queues a request to the backup system to copy the entire file, while a minor change under the Mac system queues a request to copy much smaller file(s), with an obvious improvement in backup performance.



Both OLs were written by Microsoft. IMHO, the Mac system is superior if only from an efficiency standpoint. I'd like to know if Microsoft intends to change Windows' Outlook to the better method or -- even better -- have they already done so?