I am the person who took the trip to find relatives in Calabria in October. Now, finally, I would like to ship the kids some NYC T-shirts. I know shipping OUT from the Italian post office is notoriously not great. What about shipping US post office INTO Italy? Or should I send these packages another way? I know--not really a trip question but I did write a very long War and Peace of a trip report. Thank you

I ship stuff to Europe (Poland) from Canada frequently, however, never through the Postal system.
DHL seems to be the best in terms of pricing and service.

Find a shipping center that deals with different companies, something like this:
https://gmxworldwide.co/

Don't know the Italian postal system but the Polish is stuck in the 19th century and provides services for customers born in the early 20th century.

I loved your trip report.
I have sent things to friends in Italy, not through the US postal system, but through the Canadian one and there was no problem at all.

If they are t-shirts, I'd just put them in large envelopes (padded if you want but just any heavy duty envelopes would work) and send them through the postal service. A t-shirt should weigh maybe 5 or 6 ounces so you might be able to get more than one into an envelope.

If they were large / heavy-ish items I'd use DHL but for things that are light and soft, USPS is just fine. Envelopes up to just under 1lb will cost about $15. Over 1lb rates go up quite a bit.

https://pe.usps.com/text/dmm300/Noti...MC4wLjA.#_c341
https://www.usps.com/international/f...al-service.htm