The invention relates to a separator device (18) comprising a passage zone (40) through which the articles pass and which extends between drive means (20, 30), retaining means (24, 34) for retaining an article relative to another article, and suitable for separating them mutually, control means suitable for activating and deactivating, independently, each first and second drive means (20, 30), and each first and second retaining means (24, 34). The drive means (20, 30) are distant from each other so as to define the passage zone (40), and the retaining means (24, 34) are suitable for exerting substantially transverse forces in opposite directions, so as to suck at least one article against corresponding drive means. The invention also relates to a method of controlling the above-mentioned separator device (18), and to a postal sorting machine including such a separator device (18).