There are three major players at the low-price end of the voice-messaging industry. All require IBM PCs. (None run on Apples.) Below is a summary of their offerings:

Natural Microsystems
Natick, Mass., 508-650-1300 or 800-533-6120

Starter unit offers internal modem, automatic redial, appointment calendar, and voice-dictation modes ($249); add-on handles caller responses based on touch-tone replies ($200). Other systems accommodate from 2 to 48 incoming lines, at prices that range from $1,395 to $36,000.

The Complete PC
San Jose, Calif., 408-434-0145 or 800-634-5558

Starter unit offers voice mail, sequential dialing, automatic redial, forwarding, etc. ($399). Complete unit includes all of the above plus fax, fax-forwarding capability, data modem, and a port for a scanner ($699).

Talking Technology

Alameda, Calif., 415-652-9600

Starter unit costs $295. Add-on module designed for telemarketing is $99.

Two resellers incorporate The Complete PC boards in their offerings:

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FYI Systems
San Diego, 619-276-5000 or 800-833-6611

Includes The Complete PC board in its Work Smarter package ($699).

DAK Industries
Canoga Park, Calif., 800-325-0800

Through mail order. To find out how these PC-based voice-mailbox systems work, dial 800-456-9678. If a man answers, don't hang up; it's DAK's own Drew A. Kaplan -- recorded for that purpose.