Our office has intra-office mail baskets all over, and (usually, anyways) a stack of empty manilla 9x12 envelopes next to them where you write the destination, throw your papers in, and then wind the string that seals it (they're reusable, not sticky). However, there are a number of times where there are no empty envelopes at the one near me, and since most of the stuff I send is approved invoices or signed purchase card logs, destined for Accounts Payable, I've taken to a habit that I've just realized is kind of questionable - looking through the outbox stack for another envelope going to AP, and just throwing my stuff in that one with whatever it already has in it.
AP has a central inbox, so it goes there anyway, and gets processed by whatever AP clerk is free next - so it's not a matter of not getting addressed properly. My question is: Is it frowned upon to put my stuff into somebody else's envelope if they're destined for the same place to avoid finding one or filling a new one out? I'm not looking at the contents, and I've never given it a second thought until recently it occurred to me that others might feel violated if they knew I was piggy-backing on their mail.