OPINION OF THE COURT

Memorandum.

The order of the Appellate Division should be affirmed, with costs.

According to an affidavit of service by mail submitted by defendant, a copy of a conditional order of preclusion with notice of entry was placed, postpaid, in an official depository of the United States on December 12, 1979. Plaintiffs never complied with the order, and defendant moved for summary judgment dismissing the action in March 1981. Plaintiffs opposed by claiming that the conditional order had never been received. Specifically, plaintiffs’ attorney averred that it “appears” that the order was mailed, but his office “never received that order,” from which he could “only surmise that this document was lost in the mail, since it was never delivered to our offices.”

A properly executed affidavit of service raises a presumption that a proper mailing occurred. By statute, ser*945vice is complete upon mailing (CPLR 2103, subd [b], par 2). Plaintiffs’ papers raise no question of fact as to whether proper service was made.

Order affirmed, with costs, in a memorandum.