I've also gotten a lot of stuff from myself, mostly things from internet sims I ran earlier today. Earlier today, I put a virus into the wild. After starting a new, virus-free sim, I received the virus again from the internet.
If it is from 3 months ago, then I suppose that what happened was that the robot was sent into the outbound folder a few months ago, and it remained there since there was no internet connection. Now that there is a connection, all of your unsent robots are being released into the internet.