I don’t know if “God” is a preacher or a businessman whose company has a distinctive name or initials. I’m happy to see him registered with MCI, however. When I went looking for “God” earlier on the net, the computer said in its literal way, “God not found. Enter a postal address or TLX (Telex address).”

I still can’t scare up “Satan,” at least electronically; but MCI’s reply to my last “God” entry showed both the breadth and versatility that MCI and other systems may acquire if E-Mail boosters are right. The devil actually may be on MCI any day now. Several hundred thousand Americans are hooked up to one mail net or another, and more than five million should be tapping out messages that way by the end of the decade. In Virginia a financial planner has used E-Mail’s speed to save a $300,000 deal threatened by a legal deadline.

With E-Mail you can:

● Send messages computer to computer within an office or around the world. At their convenience recipients can flash messages across their screens or print them out.

● Use a computer to zip messages to special centers near recipients. The centers print the messages, then deliver them by courier or local mail. That’s how you can overcome one of the original drawbacks of electronic mail—the other person’s lacking a computer on the same network.

● Send and receive messages via the Telex network—which, of course, is why MCI Mail politely asked for “God’s” Telex number.

“E-Mail can be nothing more than the computer equivalent of a telephone-answering box ... storing messages for people to read when they have a chance,” says Steve Caswell, a consultant who edits Electronic Mail & Micro Systems, a leading industry newsletter.

“At its most complex level, it’s a very intelligent ultimate communications device.”

Electronic mail’s roots are in the telegraph, Western Union telegrams, and Telex machines. Computerized E-Mail has sprung up in the past two decades; it grew in the military and academic communities and spread to government agencies and high-tech companies like Texas Instruments. Within the past few years, thousands of home users and other businesses have jumped in.

Competition is keen. The Western Union man is on MCI because he wants to see how it stacks up against his company’s own E-Mail operation, EasyLink. GTE Corporation and International Telephone and Telegraph offer E-Mail service. So does The Source, which lets companies set up their own E-Mail networks without investing in giant computers. Instead, they piggyback on The Source’s computer bank in the Washington, D.C., area. Users can dump messages into The Source’s computers over phone lines or log in to see what messages await them.