Then again, if they pay every month, what can you do. The easiest thing to do is check their trade history, if they don't trade, then don't make an offer.

I will say I have received emails a couple months later with apologies such as "in process of moving" or "big xxxx has happened".

It can be tough, which is one reason I don't mind having 2-4 unmanaged teams that might have an Edgar Martinez or Raffy type player that you can pick up for FA picks.