The parcel must be securely Packed. Forward items that can injure postal employees or to damage other parcels, it is impossible. When shipment complete customs Declaration with the description of all of its content, forwarded to Spain.
You can send only parcels with a stated value initially of limited value. You cannot send fragile and bulky items. It is forbidden to send the money and bonds, objects of art older than 100 years, minerals and rocks, expensive philatelic objects, original documents, biological drugs, etc.
As in all EU countries, to send to Spain a limited amount of cigarettes and alcohol. Limits weight up to 2 kg are there for live seafood, honey and other bee products, as well as various meals for children, feed for animals in factory packaging.

Limit up to 1 kg are there for bakery products, chocolate, various pasta, concentrates.
In General, there is a restriction on the importation of products or goods of total weight over 30 kg.

It is strictly forbidden to send to Spain products containing meat, including poultry meat, sausages, canned meat; dairy products; animal feed containing meat or milk.
The standard package is one whose weight does not exceed thirty pounds, and its length for all parameters not exceeding 75 cm. The other parcels are informal, and during the transfer they will be charged.
Upon detection of the parcel that exceeds the allowable dimensions or contains prohibited products, it will be confiscated and destroyed, while a second violation possible penalties.