Processing the check is IRS's responsibility. If they accepted your check, but do not process it, it is their fault. Once they accept your check, your end of the deal has ended. A while back, I got a notice that I did not pay my state tax.
1 The xiphoid process (Latin: processes xiphoideus) is a small triangular cartilaginous extension of the breastbone.
1 Sometimes the pain and tenderness in xiphoid area may be due to problems related to heart, gallbladder and bone diseases. 2  Therefore it is necessary to distinguish between symptoms of pain and tenderness in the xiphoid area due to other diseases and that of swollen xiphoid process. A direct injury to chest and particularly a blow on the xiphoid process can cause swelling of xiphoid process. 2  As a result the xiphoid process becomes tender and painful. 3  The condition is often called xiphodynia.