Hmmm, in the south ( or even Mid Atlantic where I am) it isn't a good idea to ship wet because, esp. when it starts to get hot outside, can cause some to rot or get moldy. I do ship FRESHLY DUG plants, but plants are washed, dried, and then wrapped in newspaper ( dry.) Then we are at the total mercy of the USPS to get them there in 2-3 days so that they still look fairly fresh. Any daylilies are going to yellow some over the trauma of being out of the ground and shipped but they will recover in a few weeks. That is normal. Don't over water new plants!! Van Sellers taught me years ago that more new daylilies are killed by over-watering than anything else. Plant them, water them in, then leave them alone. Water 2-3 times a week. The ground is still so cold here that I am not putting anything new in the ground for a couple weeks. When you take a plant ( esp. one that has been shipped from a warmer climate than you) and put it in colder ground than it has been used to, that can set it back even more. One year someone sent me plants from LA earlier than I'd requested, and because I was heading out of town, I planted them in the ground. Almost all of them rotted within weeks. These were new expensive ones too. Ugh. Nowadays I generally tell sellers early May at their convenience and if the ground hasn't warmed up yet, will pot them up for a few weeks.
So far this season, USPS has done OK. I'm hoping that black hole that a few packages fall into each year has disappeared. Last year it was located somewhere between LA and TX!!