Yes, although you should know that over the last two days, the offline selling system has been up and down. There have been more server locks than usual lately, and this seems to be part of it.
You can sell things offline by putting them in your house vault. If you haven't found it already, click on your door from the inside of the inn room. It's only two slots, so it's a good idea to put strong boxes in there as soon as you can afford them. When you click on your bulletin board, there should be a section labeled "vault." Price your vault items, and they will be for sale for 24 hours.