<p>one school I'm applying said that I just send the rcommendations online.
But doesn't the teachers have to sign the recommendation?</p>
<p>You left out some info. Does college have form for teachers to use that the teacher can do and send on-line? In that case, they mean for the teacher to send it on-line by filling out that form. If no form or no other specific on-line method, then possibly they are suggesting that teacher’s letter be prepared, scanned into pdf format and sent by him via an email. </p>
<p>As to handwritten signature it is not necessary if the teacher is filling out a form that is provided on-line. Moreover, if the teacher just sent an email with his recommendation that would be enough.</p>