A rare reason to make a call

Dear Rejecter,
I moved this past summer. Before I moved overseas, I sent a query to an agency that doesn't have a website or e-mail address. My relatives in the US informed me that the said agency replied asking for a full. I sent the full from my current country of residence in September. (The letter for the full came in July). My question is, should I call the agency to know the status of my manuscript? I know this is a no-no, but I did not send the package as certified because it was going to a PO Box, and for the past month, many letters have gone missing in the post offices around here.

I really want to make sure that they received the manuscript since they are the only agency to ask for a full. Thank you in advance.

The agency has no email whatsover? Check that it's a legitimate agency at Preditors and Editors, do a web search again for the email, and if you find nothing, I think you're justified in making a call. On the phone, be brief. Just ask them if they received it and if they have an email address, not whether they've read it or not (they probably haven't).