[mojonixon]

If you're interested in how the pros do it, about 5 years ago I temped at a bulk mailer--mostly medicare checks to doctors--using pitney bowes(IIRC) equipment. The machine I was running was organized in an L shape 20'x20'. One side would strip the letter off the continuous paper stack, collate it, fold it, and seal it in an envelope. The second side would stamp it and stack it in postal bins. A bad day I would do about 20,000 but if I had everything calibrated and the guy on the shift before didn't muck things up too bad I could get close to 50000 in an 8 hour shift. The system I was using rather old and temperamental, so I wouldn't be surprised if modern equipment is an order of magnitude faster.

Once the machine was running I didn't have to do much besides put envelopes in the hopper, but the noise, paper cuts, and opportunity to lose a finger while clearing a jam made it a horrible job.