Why can't I receive-mail from one particular e-mail address?

Why cant I get email from iammccoy24@yahoo.com?

ive gone in as a new email because i havnt used it for ages so i opted for a new email address, but its not accepting any i put in, why?

i am able to recieve email from all others,, but i cannot send email to anybody,, it says sent ..but it was not recieved by the reciever. inface i tried to send a mail to another of my email account, it didnot work,, but after sending it says as sent...

like I said, I use another account not this one, to send out email blasts about the adult parties I throw, all the people on my mailing list have inquired about the parties, I blasted out about 700 emails this morning, and now when I went to log in it...

I know how to forward ALL my email to another address, and I know how to forward an individual email MANUALLY, but I want to set up an auto-forward for any email i receive from a particular person. My work blocks hotmail, but not yahoo mails, but i cant...

OK, here's the deal.. I had 2 email address, because myspace wouldnt let me register 2 pages to the same email. so i got another yahoo email address.. the problem is.. i don't remember what it is, and myspace customer service is no help, and neither...

I was given a default email address with random words and numbers to upload to my flickr account but I want to use another email address to give people so they can upload pictures too. I cant advertise some random email address and flickr wont allow...

My account has been blocked for mass emails sent by some common virus, and now I don't remember my alternate email address where the code has been sent. the full alternate email address is not shown, and i don't remember what the alternate email is....

i try to send an email and then it sends me a email saying that the one that i sent has failed and this is the second time i have tried and it still wont let me and i also have the email address correct and everything what can i do to fix this?