According to my divorce decree, I was awarded 50% of my (ex) husband's 401K. I had to pay $250 to an attorney and open an IRA, forwarding him the account details so this transaction could be facilitated. I sent in a check April 17, 2013 and as of today (June 27, 2013) the check remains uncashed. I called his lawyers office to just to inquire where my check was and they told me they would look into it. In the meantime, they contacted my ex that I have, in fact, started this ball rolling and he is refusing to go along with this. He is sending me e-mails bullying me not to pursue obtaining half his 401K. What sort of recourse do I have with this?

Contact the holder of the 401k. They should be able to handle it and tell you what paperwork is required. Splitting one in a divorce happens all the time.

Also not a good idea to contact your ex's lawyer. They work for him and not you so don't expect any results.

I'd take the shortcut by going back to Court to hold him in contempt, taking his threatening emails with me.

As far as the Attorney I'd write a letter, send it certified and return receipt requested. Demand that some action be taken.

To get his 401(k), you have to file a QDRO http://www.dol.gov/ebsa/faqs/faq_qdro.html. This is probably what the attorney is preparing.

Agree, you never ever talk directly to the ex's attorney, you talk to your attorney to talk to his attorney. But if he does not transfer it, take him back to court to enforce it