this is MEDCO.  it is a legitimate drug/prescription mail order company.  probably trying to reach you to tell you your meds have been mailed.  federal law prohibits leaving that sort of info on an answering machine.  might be the pills for the std your spouse does not know you have, or they might have dialed a wrong number, and then your neighbor would know about your medical condition.
i get calls from them 2-3 times a month for the meds me and my wife take.

No message left.

no call was left 2-2-09