"[T]he date an item is delivered to the USPS is no longer relevant for determining whether a filing or notice is timely mailed. This creates uncertainty as to when a postmark will actually be applied, particularly for time-sensitive benefit plan documents.... For large-scale or mass mailings, [alternatives] may be impractical or cost-prohibitive. In such cases, plan administrators should strongly consider mailing well in advance of the deadline to account for potential delays before a postmark is applied."  MORE >>