I saw somebody mentioned that you should take you package to the P.O. as early in the day as you can, to get it on the way as soon as possible. That's often not helpful. At my local P.O., the package isn't leaving until around 5PM, whether I'm there as they open for the day, or drop it off just before closing. It doesn't matter. The pick up times are set for specific times of day. Ours is 5pm. So call you P.O and ask, before you play beat-the-clock to get there early in the morning.
I had a long discussion with my post mistress. She said there's no way to avoid the machine sorting/conveyor belt handling that packages get. They ALL get the same, fragile or not. The only time your package markings matter at all, are the short times when people actually touch them. I've started putting pics of the eggs, what the hatchlings will look like, and what they'll look like as adults, on the box. I also put "Live embryos, please handle with care" and "fragile".
So far, my eggs have been delivered intact, and carriers have commented to the people receiving them, that they enjoyed the pictures, and said they wished all eggs were marked as well. My theory is that it will get the attention of folks handling them, and
maybe they'll be a bit gentler, maybe put my box where it won't get crushed by that other big
heavy box over there...
I don't think they go out of their way to hurt our eggs, I think they just don't notice ordinary "fragile" markings, among the thousands of packages they handle. Sure, there's a few jerks here and there, but I don't think they're the majority.