Where a nomination is received by letter bearing the postage meter date without any postmark placed thereon by the post office, this postage meter date shall be considered to be a postmark for the purposes of this rule, if the letter is actually received within 7 days following the closing date of the event. Receipt a nomination by letter after this time shall not be a valid nomination or payment to any event. The metered date must conform to the postmark date as previously set forth to be valid.