postmark deadline on sunday?

<p>i have one more thing i need to send them, but i may not be able to get it out saturday, and the deadline is sunday... and there's no mail on sundays. if it was postmarked on the 21st would my whole app be considered late? </p>

<p>is there any way i can get it postmarked on the 20th? i know some small colleges are a little lenient with the dates as long as everything else is in.</p>

<p>oh wait... i just realized there won't be any mail on monday either... hmmm.</p>