I used Western Union here, service is very good.
Very good service and very nice people ! Send a packet to France for a good price over sea.
You should take a number to get in queue. When I visited, there were 12 people before me and it moved quite slow. If you need only stamps, there's a post clerk in the Circle store next by - you can enter the store through the post or from the street.
3 times I've walked here now to post something. The website says it's open. The window on the post office says that it's open. But when I get there 30 minutes later, it's closed. I don't understand why they can't just update the information online when it's closed. There was a bunch of people outside today in the same situation. Ridiculous
If you wanna send a package it will not be handled within minutes, don't go there if you are in a rush. Suggestion, find your own packing material before - will cost you less and save time. Not because the material are expensive but because they will use the big package and it influence the costs.
It's clean and has AC which is a plus but in functioning as a Post Office, it's pretty bad. I've been waiting about 20 minutes now to send a letter and am watching some of the counter staff watch TV... when in Rome and all but this Rome has pretty poor service standards.
Ubud Post Office is on Jalan Jembawan. The marker on the map is in the middle of rice fields, outside the main town. Maybe someone can move it to the correct location.