My message send by my YAHOO mail to a certain adresse at WANADOO.FR can' t be delivered. What's the problem;

Answer 1

The address you are sending your mail to either blocked you from sending them anything or that address no longer exists.

Answer 2

What does the "Undeliverable message" Message say? Ussually it will list the problem i.e "This user has exceeded his quota", "Account Inactive", "mailbox not found"

- doublecheck address' spelling..
- make sure no unseen characters e.g a dot at the end.
- Make sure You have the charactes right, e.g Capital i appears like a small L.
- Try typing the address in quotes eg "Someone" , Try to remove the quotes and try again eg [e-mail]

Hope that helps..