Italy

There are quite a few post offices in Rome, many maps show them and most GPS systems will find them. If you Google "post office rome italy" you will see several dozen. If you scroll around this helpline archives you will find a number of threads, most of which (like myself) advise against mailing anything from Italy. It is by no means certain that anything from post cards to packages will arrive. It is also very expensive. If you must mail stuff from Italy I strongly advise you to go to Vatican City and mail from there, you have a much better chance. There are postal counters near the toilet block near the entrance to St Peters. Good luck.

Word of caution. I sent some personal items back home from Varenna on Lake Como in 2008. I'm still waiting for them.
Two weeks after I returned to Los Angeles I did get a 4:30am PST call from a man who spoke little English telling me I needed to provide my passport number so he could send me the package. I asked him to email me the request and he did. When I replied I had the package confirmation number and that was the ONLY number he was getting from me I never heard back, nor got the package. Got the Italian consulate in LA involved. Had them email him. Nothing. The package contained a pair of shoes, my favorite sweater and a few other things. Nothing I can't live without but it did turn me off to mailing anything from Italy. That said, Varenna is not Rome but the man who did contact me had an email address for a postal center in Rome. If the stores where you make your purchases will ship the items to you and if you buy them via credit cards at least you'll have a record to trace. Love Italy but wouldn't even send a postcard home from there.

I haven't done what you are asking, I considered mailing stuff home from Germany one time but didn't because of the price - so ended up carrying it on and checking my normal bag. The Vatican is considered more reliable and I don't think the cost is any different than mailing from Italy.

http://www.ricksteves.com/graffiti/helpline/index.cfm?topic=60645 I would suggest, in order: 1)bringing an extra piece of luggage, like a flat-in-the-bottom-of-your-suitcase duffle bag and check it (probably for free, but check with your airline) on the way home; 2)FedEx/UPS/DHL if it's something delicate, expensive, etc. - it MUST get home in one piece, and not rummaged through, and 3) the Vatican Post Office. Ideally, if you're planning large/heavy purchases you can have the shop ship them home for you. It's a crap shoot; good luck!

The problem was not giving the passport number and it was not unreasonable. The passport number is of little value anyway. Any products shipped back to the US goes through US customs and I assume they want to tie that package to someone. We had a merchant ship some purchases from Germany last winter. And guess what ?? They wanted a passport number. You could a shipping service like Fed Ex, Dahl (if still around) UPS but they are are expensive.