I had the same question as you did about how long vacuum packed smoked salmon was good for, we were planning on sending it as Christmas presents. According to the US Dept. of Agriculture it is safe to eat for 4 months if vacuum packed. Don't have the link I used as I did the research before last Christmas. No reports of any sickness from any of the presents we have sent out, some went as far as Indiana via UPS ground which took about 5 or 6 days. I would think that yours should still be good.
Good luck and tight lines, Jeff laugh laugh