Getting letters and small packages mailed from overseas

Hi, yes you can receive packages at your local Post Office, if it has an " aduana office" there.  if they don't  (ie: Plaza Concordia P.O) they'll leave you a note in your box telling you that you have received a package that need to be checked for aduana and  where to collect it, It can be at P.O del Dorado or the P.O in Carrasquilla, or any other office where they have aduana.

I'm not sure if you pay taxes based on the weight of the packages or the value on the invoice, because the only time I received something  (a saxophone) I asked, but the person in aduana, didn't know/want to reply,so he just looked at the box and the invoice and told me, it's going to be $80.   
if the content of the package has not a high value, it might be good to state on the invoice that it's a gift or a sample, so if you pay taxes based on the value, they won't be that high  
Using correos nacionales is definitely way cheaper than any private company, but most foreigners avoid to use it because it can take ages to receive something or the item might get lost.

Hope this help.
Cheers

Thank you so much! This is very helpful.

What I'm planning to get mailed over is something of hardly any value, so I'll just go for having it marked as "gift" on the customs declaration form.

- Adriano

I have a mailbox at Mail Boxes Etc. in Panama City.   It is $27 per month for the mailbox and includes up to 2 kilograms of letter mail or packages sent from anywhere in the world.  When a package arrives, MBE sends an email notification.  They will hold the package until you pick it up, and if there are additional postage fees above the 2 kilograms, you pay at that time.  So far, every package that I have received has arrived quickly and in good condition.  MBE accepts credit cards for their fees.