The answer depends upon which country you are sending the mail from.
For example, the United States Post Office has the following basic rules when it comes to foreign addresses:
We recommend that you print your delivery addresses in all uppercase letters. If possible, addresses should have no more than five lines.
The full address should be typed or legibly written in English—using Roman letters and Arabic numerals—and should be placed lengthwise on one side of the item. An address in a foreign language is permitted if the names of the city, province, and country are also indicated in English. Global Express Guaranteed destination addresses must be written completely in English.
The last line of the address block area must include only the complete country name (no abbreviations) written in uppercase letters.
Foreign postal codes, if used, should be placed on the line above the destination country. The following shows the order of information for the destination address:
LINE 1: NAME OF ADDRESSEE
LINE 2: STREET ADDRESS OR POST OFFICE BOX NUMBER
LINE 3: CITY OR TOWN NAME, OTHER PRINCIPAL SUBDIVISION (such as PROVINCE, STATE, or COUNTY) AND POSTAL CODE (IF KNOWN) (Note: in some countries, the postal code may precede the city or town name)
LINE 4: COUNTRY NAME (UPPERCASE LETTERS IN ENGLISH)
The following are examples of properly formatted delivery addresses:
MS JOYCE BROWNING
2045 ROYAL ROAD
LONDON WIP 6HQ
ENGLAND
MS JOYCE BROWNING
2045 ROYAL ROAD
06570 ST PAUL
FRANCE
The following format should always be used for destination addresses to Canada:
MS HELEN SAUNDERS
1010 CLEAR STREET
OTTAWA ON K1A 0B1
CANADA
As you can see, for the most efficient delivery from the US to a non-US address, it's best to use the AmE standard of address, which means the house number is listed first followed by the name of the street.