Email issues - bounces back to original page

My wife is having issues getting her emails, her last bit of address is blueyonder. Have tried absolutely loads of times to get in but keeps saying same thing or just bounces back to the original page. Somewhat frustrating and makes us seriously angry, we're in the 21st century why is it so hard. Tried 150 well that's about as much use as a waterproof tea bag in a chocolate tea pot. 

 

 

[MOD EDIT: Subject title changed for clarity]