How to stop AddressBookSourceSync in Mojave

I keep getting the "Your system has run out of application memory" and "Force Quit Applications"

message. Checking the disc I have a 2 TB hard drive and I seem to recall maxing out on RAM since you can never have enough it seems. Checking Activity Monitor the top three users - by far and by order of usage highest to lowest are callservicesd, soagent (sometimes the latter two switch places), and AddressBookSource Sync. I do not use iCloud at all. I do have Outlook on my iMac for work and wish I could figure out how to unlike "Mail" to that, since I don't use "Mail" (would just as soon delete.) Anyone else experiencing this - this started when I upgraded to the new OS about a month back or so.