That is the purpose of postage, to allow you to mail letters to anywhere in the world. The stamps of the country of origin of the mail are used for postage.
No, you have to use stamps from the country of origin of the mail. In this case you will have to use Italian postage stamps.
No. The Universal Postal Union requires you to use the stamps of the country of origin.
No. The stamps used must be those native to the country in which the items are posted.
As postage to mail something like a letter.
Of course
The entire purpose of the Forever Stamps was that you can use them for one ounce of First Class Postage forever. No additional postage is necessary.
Yes, as long as the total postage affixed equals the current postage rate.
Yes, that is what postage stamps are for, to mail letters from your post office all over the world. Being that the US Post Office is going to get the mail to Great Britain, the US Post Office should get paid. The Universal Postal Union provides for the compensation between countries.
To mail a single letter to Canada, the stamp must be equivalent to the postage cost. As long as the stamp is equal to the postage, any letter can be sent with any kind of postage stamp.
Have to use postage from country of origin
You can use regular postage stamps, but it will cost more to mail a letter outside the US. The cost to mail something from USA to England depends on what you are trying to mail. It costs $1.10 for a one-ounce letter. See related links for Postage Price Calculator to see what it would cost to mail other size items and packages.
Yes u can