My son signed a rental lease 6/08. 8/12 he was served with a foreclosure notice stating that he may terminate his lease with a ten day written notice to landlord. "You may be liable for rent due under the agreement prorated to the effective date of the termination"
So he found another place to live. Signed that lease 8/22. 8/25 gave lease company notice they were leaving 9/4. 8/27 a notice of foreclosure dismissal was filed after landlord paid $7386.88. Now the landlord says he will sue if they move out. My son is in the Coast Guard & is not getting much help from their legal department. We want to help him move this weekend! Help!

I think you may be stuck. The house was not foreclosed on, so if the notice didn't come from the landlord, then it's not legally binding, since his rental contract is with the landlord, not the bank. So your son has to abide by his lease the same way that the landlord does.

As Froggy7 pointed out, the outcome will depend on who sent the notice that the lease may be terminated and if that person had the authority by law to do so.

Tell us who sent the notice and also tell us the state where the property is located so that we may look at the law.

Lisa is right, the issue revolves around who issued the notice and whether they had a legal right to do so.

However, I would go ahead with the move. No matter what, your son acted in good faith based on documents he received as seemingly official. If the landlord has a cause of action its against whoever issued those documents. If the landlord does sue him, then he can turn around and sue whoever issued the letter.