service through a p.o. box

I think they could give you a notice that there was a certified letter waiting for you and you would have to bring that notice to the post office where you would sign for it. And no, they don't rig the box so an alarm goes off and no, they don't have someone waiting, I'm sure....

The post office will leave a notice in your PO box letting you know that you have a certified letter waiting for you. They will usually keep the letter for so many days and if you don't pick the letter up, it get's sent back to the original sender. If it is a summons from a court, they might try other means to get you served such as publicizing it in the newspaper.

In Texas, you CANNOT be served for a civil suit by certified mail unless the plaintiff signs an affidavit and gets a Court Order allowing service by certified mail. Generally, they would have to show that they cannot find your physical address and have made reasonable efforts to do so.

I used to have a PO BOX and when I was served papers it was at my home address and later and my work address.

Check your PO Box regularly so that you don't miss any important letters. I think such important legal papers are sent in person and you have to sign for it.