Needless to say, there is a bit of snow on Mailbox this week and if you're heading up, you can expect to be waist-deep in powdery white stuff like this for the last half mile. My hiking partner and I tried to power to the summit, but turned around about 200 yards from the top because we were both fairly interested in living and not really that interested in falling off a mountain trying to get to a mailbox. I felt bad because my hiking partner hasn't been to the top before, but I promised to take him back on a day that looked less like Siberia.
You're going to encounter snow early and often, so I'd say microspikes and poles are almost a requirement until some of this snow melts. This trail is already dangerous to begin with and footing is quite poor in conditions like this. I would advise people to skip that last stretch as it was quite sketchy and we both felt like we pushed it too far even getting that close to the summit.
I have a love/hate relationship with Mailbox, but it was still a really enjoyable hike, and the periods of misery you have on the trail are generally outweighed by a solid workout, some great views and a sense of accomplishment. But for the time being, Mailbox and I are not on speaking terms. Three feet of snow on this sadistic postal route is no good.