<p>My prof mailed my letters out and I don't believe he signed the seal of the envelope. Was he supposed too?</p>
<p>Yes, it’s best if he did. Call the schools and ask if they will accept the LOR, and if not, what to do in such a situation. Worst case, they could always resend them.</p>
<p>its fine don’t worry about it, most proffs don’t</p>