Definitely keep in mind that right or wrong, these hosts are unusual as far as most commercial services are concerned and it can reveal annoying edge cases in their software.

I'm constantly annoyed how much trouble I have using a .health domain (looking at you T-Mobile). I can't imagine using this many subdomains off a .us.

eBay still in 2026 can't send to subdomains.

Use something like ebay@shipping.example.com and they send to ebay@example.com

I had to check the server logs to find why I wasn't receiving any mail and now need a top level alias just for eBay to handle their broken mail infrastructure.

True. I struggled to get signed up for my COVID vaccine back in 2021 because Walgreens wouldn't accept that my totally valid .rodeo email address could possibly exist.

I still use that domain for most corporate accounts. Currently, my wireless carrier refuses to believe I exist in some of their systems (but not others) because of it.

Fortunately, escalating complaints with large corporations with shitty practices is a hobby of mine.

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