Is a company obligated to pay severance by verbal agreement, emails and practice?

Our company is moving to another state and most of the employees were told that they will not be going with the company and will be laid off, including myself. We were then told that we will be getting 2 months severance. This was verbally told to us over 2 months ago and I have email trails stating they will pay us the severance. This company have paid severances in the past to other divisions, though at a higher amount than what they are paying us (i.e. 3 months+ to division A vs 2 months we are getting). They mentioned several times by email that the severance letters are coming but so far nothing. We are getting more and more concerned that they are going to renege on this deal. So is the company obligated to pay our severance even though we do not have a formal letter? Will verbal promise, emails stating they would and practice in the past be sufficient for us to challenge them in case they renege?


Once last thing. I and another executive were told that if we stayed until 10/30, we will also get a "retention bonus" to help wind down operations to the very end. Now we were told that they decided to take away the retention bonus but we still have to stay to wind down operations. Are they obligated to pay us the retention bonus, even though it was told to us verbally?

I appreciate any answers that you can provide me. Thanks.