The problems you get with the post office are that they charge a handling fee to open up the boxes on your behalf to decide what is inside.
What you need to do sometimes when ordering of companies, or individuals, is get them to mark the boxes EXACTLY what is inside of them. They also need the correct paperwork.
Not everything is checked however.
but this is the important bit IN NO CIRCUMSTANCES SHOULD GOODS BE SENT TO THIS COUNTRY MARKED AS 'GIFT' WHEN THEY ARE PURCHASED ITEMS!
Until recently (stopped because i got too busy) i had a business and traded on ebay internationally. as such i looked into the international thing. If you receive goods marked as gift and they are not (and believe it or not, customs can tell the difference and are well up to speed on the types of items that are not a gift) then you will be done for illegal imports. If they pick you up that is! And you still get charged the handling charge and VAT. Its just not worth it.
Chinese electronics are the worst offenders because they think that they are helping you! Its not however the overseas companies who get the bill at the end of the day.
From what I can understand, the category of gift is an item which is being sent to a family member and will be for their soul use. Anything else isn't.
Finally, if you want to send things to other countries do check out their import duties. You can't send anything of an agricultural source (soil, plants etc) outside of the EU.
And you can't send clothes to Australia
The rules change constantly, so be aware!