Expression: "By the time..."

Hi

Do you find the following lines correct and natural, especially the red? Any suggestions are welcome.

Tom

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And I hope that by the time you receive this email you are no longer under the weather. Well, on second thought, I think we should invent some new phrase instead of “by the time”, because we are no longer as in the old days writing letters which need to be posted and which would reach the recipient in two weeks’ time at the least. This is the day of electronic mail, which travels with the speed of light. What do you think?
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(Interesting question, actually: which is faster, email or the speed of light?)

Electricity moves slightly slower than light, due to resistance in wiring, but it’s close. Light moves at 3x10^8 m/s, electricity at 299,792,458 meters per second. (That’s an approximation, since resistance will vary with the type and size of the wires used.)

Email, however moves at about 1/3 the speed of light, apparently. It’s not the speed of electricity that governs email, but rather the information processing time of routers.

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A fascinating fact. Thanks, Skrej.
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