E4 Servs., Inc. v National Liab. & Fire Ins. Co., 2014 NY Slip Op 51124(U)(App. Term 1st Dept. 2014)
“In opposition, plaintiff’s “denial of receipt, standing alone,” was insufficient to raise a triable issue (Badio v Liberty Mut. Fire Ins. Co., 12 AD3d 229, 230 ; see Trusts & Guar. Co. v Barnhardt, 270 NY 350, 354-355 ; E4 Servs., Inc. v Lincoln Gen. Ins. Co., 43 Misc 3d 136[A], 2014 NY Slip Op 50678[U][App Term, 1st Dept 2014]). Nor did plaintiff provide a sufficiently detailed showing of its own procedures in retrieving, opening, and indexing its mail and in maintaining its files on existing claims to raise a triable issue of fact”
You are starting to get the sense that proving a lack of receipt is as cumbersome a process as proving a document was mailed.