You can always create fake user on your domain and make it appear as if it came
from sales.staff@
yourdomain.com.
If you really need to hide
yourdomain.com, then you're into email spamming techniques
and we will not discuss those here. The necessity of this is extremely questionable.
If your recipient is that sensitive, then someone needs -- help.
I would think that international sales would however, be conducted in the language of
the recipient and having staff that is bilingual is always a great asset
