I needed to drop off something at post office today.  Signs on door state no entry without mask.    I went back and grabbed one out of my car.  Go inside just me and two workers.   One worker has mask as a chin strap and the other none.  I asked so no mask required?  They both said yes you have to wear a mask in all federal buildings or we have to make you leave!   I said and the workers don't?  Yes we have to wear them as well.   I said Oh Ok!   They both said we are fully vaccinated!  I said and so am I.