What are the regulations of sending an envelope? Can I put an envelope that has some small clips in the mail box and they take it?

Kurt,
Only thing I would do is use a padded envelopes. I you knew what a letter sorting machine can do to a piece of mail with something unusual in it, you would see what I mean :)

Pretty much anything goes BUT remember the letters go through machines and clips should be put into a flat envelope or you will be rolling the dice as to whether a machine wtih high speed rollers will "eat" your envelope. Paperclips are not a problem but bottlecaps are a sure bet for disaster in our machines.

Well, they are clips for a door panel. You think if I line the envelope in tissue it will be OK?

Taped to a piece of carboard in a 8 x 11 flat sized envelope is the best choice. If that is not possible then taped to a piece of carbboard and then wrapped in a piece of paper should survive in a normal envelope.

OK , thanks Redrum.

An 8X11 envelope is a good idea, they are sorted by a flat sorter. Do as BillK suggested and use a padded one.