I consider something to be domesticated when it has enough genetically-originating physical and/or behavior changes from being kept in captivity that it is incapable of surviving in the wild without human interference. It does not have much to do with intelligence, as animals such as silkworms are generally considered to be domesticated and are not intelligent at all (their domestication is largely physical - I've read they can't crawl more than 12 inches in search of food).
Most domesticated vertebrates have a combination of heritable physical and behavioral differences that set them apart from their ancestors. For example, domestic cats and dogs have comparatively smaller brains than African Wildcats and Gray Wolves, respectively. They also come in a wide variety of human-created shapes and sizes that would almost certainly be deleterious in nature.
As for snakes, I am not sure if any can truly be considered domesticated (yet). If you released into the wild a normal cornsnake derived from lines that have been in captivity for decades, would it be able to survive? I would say most likely yes, as there is little or genetic difference between that snake and its wild counterparts. Physically and mentally the two are essentially the same.
But then we have the morphs... Would a high-end amel bloodred corn be able to survive in the wild? Probably not. Some morphs would probably be able to survive (such as aneries or genetic stripes) and would eventually just blend in with the natural population. I suppose it is reasonable to say that some types of snakes are "half-domesticated".
But thinking about the question further, does it even matter if snakes are "domesticated" or not? Consider the reasons other species of animals were domesticated - more flesh (for meat), easier training, companionship, etc. How many of us eat, ride, or socialize with our snakes? In other words, we really have no reason to domesticate our snakes, because they are (for the most part) harmless to us and there is nothing specific we need them to do.
The definition of "domesticated" is going to vary from person to person, though, so I'm willing to bet other people are going to say something completely different from my post.
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- Natalie
(San Francisco Bay Area)
1.0 Banded California King
1.0 Mexican Black King
1.0 Goini Kingsnake
1.0 Bay of LA Rosy Boa
0.1 San Ignacio Rosy Boa
0.1 Ortiz Rosy Boa
2.3 Kenyan Sand Boas
0.1 Saharan Sand Boa
1.2 Rubber Boas
0.1 Pickering's Gartersnake