this is an HTTP error which occurs when the file you are trying to send is bigger than the server allows it to be. in your case your transaction size is bigger that the allowed size. can you tell us the size of your transaction?
since you say you have saved the transaction, load it and instead of sending it just take a look at the size. the window will look like this:
the problem is most probably is because your transaction size is big and makes it non-standard so the nodes are rejecting it. if that is indeed the case then the push services won't solve your problem. you should try sending a smaller amount (selecting less inputs or creating less outputs) so that your transaction size comes down to standard level.
