Help with automatic answer?

Question

I am off to Spain for 3 weeks and would like to have an automatic answer on my e-mail when I am away.

I do not want to make any mistake, so please, can anyone help me?

I will write it in my language and also in English.

is this ok or is there any mistake? Or would you write it in another way?

I am off to Spain for 3 weeks. I will be back on 7th September. I will write you when I am back.¨

Answer 1

I will be in Spain for the next three weeks, please leave a message, and I will contact you on my return to the UK, which will be after the 7th of September 2008.

Answer 2

I would put "I will answer your email when I am back" although what you put isnt wrong as such

Answer 3

Put the word "the" after the word "on" and before the "7th".  Besides that it looks good.