1. A method of processing mail, in which method it is assumed that mailpieces belong to a succession of uniform mailpieces or “run”, and, for each mailpiece in the run, OCR is performed on certain information to be recognized in a zone of interest of an image of said mailpiece, said zone of interest being associated in a memory with said run so as to force said OCR thereon, wherein the method comprises the steps of: a) initializing a matrix accumulator associated with said run of mailpieces and including unitary accumulation elements that correspond to the pixels of the image of a mailpiece of the run; b) on the basis of the image of the mailpiece, identifying pixels of interest that are representative of said zone of interest, and consolidating said matrix accumulator by incrementing the unitary accumulation elements of the matrix accumulator that coincide with said pixels of interest; and c) defining, in the OCR processing, said zone of interest of the image on the basis of the unitary accumulation elements of the consolidated matrix accumulator that present extreme accumulation values; and wherein, during the identification step, at least one of the following steps is performed: for consolidating said matrix accumulator, the OCR processing for a mailpiece of the run is used to derive an indication of the spatial position of a block of pixels in which the OCR processing has recognized said certain information unambiguously, the pixels of said block of pixels constituting pixels of interest; and for consolidating said matrix accumulator, deriving an optical flap map by construction and local graphical correlation of blocks of image pixels, said flow map being indicative of local graphical movements of pixels between two images of different mailpieces of the run, the image pixels corresponding to such graphical movements constituting pixels of interest, said optical flow map enabling the movements of said unitary accumulation elements to be tracked dynamically, and thus reinforcing the robustness of detection of said zone of interest.