Alimony question

When we went through mediation, our mediator had it written in our memorandum that the alimony I am paying would not be tax deductible for me nor taxable for me. My attorney later advised me that this is not how the IRS handles alimony, that the IRS code considers alimony as taxable and tax deductible. My stbx maintains that we need to follow the original plans we agreed to in mediation. Note that the mediator is not a lawyer. Is my stbx correct, that this is our option?

The IRS rules allow the payor of alimony to deduct the amount paid and the payee must include alimony as income on their return. There are certain requirements for this rule to apply, one of which is that the alimony be pursuant to a signed agreement, or court order.