INCORRCT: Send to me the documents.
CORRECT: send the documents to me.
CORRECT: Send me the documents.

There are a few things happening here.  "Send" is one of a very small number of "ditransitive" verbs: verbs that can be followed by 2 nouns or pronouns ("me" and "the documents"). Here is a list of ditransitive verbs:  https://www.cse.unsw.edu.au/~billw/ditransitive.html

However, you almost never NEED to use  a verb ditransitively.  It's fine to just use one object: "the letter".  However, always put a 'direct object' in front of a 'prepositional phrase.' Never say or "I took to the vet my dog" or "I put in the pan the water." Always say "I th\ook my dog to the vet" and "I put the water in the pan."

Hi Thierry Ams,

Pay attention to the word order. The rules are as follows:

1. send somebody something: 'Could you please send me/us/them the documents?'.

2. send something to somebody: 'Could you please send the documents to me/us/them?'.

Hope this helps.