Proselytizing: email scheduling

It's become common in academia to put messages like "My working hours vary. Please don't feel that you have to reply out of hours." (or similar) in email signatures. I have to say it annoys me because (a) it gives the message "Look at me, I'm working so hard out of hours, but I don't expect you to be as dedicated to the job as me" and (b) there is a much better solution!

Most email programs have a 'send later' function. On Outlook, if I hit 'send later' the default time it gives me is the next weekday at 9am—you can change that, but it's usually perfect. I write my emails at all sorts of hours of the day (and especially night), but I try to make sure no one gets them out of business hours. This both obviates the need for a 'look at me I'm working late' signature line AND reduces email traffic out of hours.

If I send my colleagues a message at 9pm, I might get responses at 9:30pm, which create responses at 11pm, which either keeps people tied to their email at night or makes them face a full inbox when they get up. The people who don't or can't email all night are put at a disadvantage because their colleagues might be making decisions 12 hours before other colleagues log on.
But if the day's messages only happen over a 10-hour period or so, we don't have to be looking at our inboxes all the time. We can, if we like, answer the emails at our leisure at night or at dawn (delaying the sending), but we're not creating any opportunity for others to communicate with us during the time that's supposed to be theirs.
Occasionally I schedule messages a bit earlier (7 or 8 ) so that a person who needs the info first thing in the morning has it early enough, but in the main, I try to keep my messages between 9am and 7pm. In my last look at email each day (at about 6) I answer anything that looks brief and urgent, but the other answers can wait to be sent at 9 the next day.
Keeping things more or less in business hours sends the message that business hours = when we do business communication. If people on my team are night owls who want to be working at midnight, the work they should be doing ≠ dealing with my midnight emails.
The email signature lines about "I email at all hours" *perform* caring about others' time. Scheduling emails during business hours enacts that care!