[BeetleB]

When I set it up, I knew it could be annoying, which is why I automatically whitelisted everyone I knew. I was seriously concerned people would rather just not be able to send me emails and will willfully ignore my emails, but as I pointed out, that's the exception rather than the rule.

And I am proactive. If I see an email in the quarantine folder from someone I want to be on the whitelist, I press a button and he's in. This isn't a hard line, binary, black and white situation. I can and do place people in the whitelist.

If I've requested something from someone, I don't expect them to respond to the email, and I usually reply back to them with an apology about the email. So far, no one has complained.

And I don't use captchas. There's no need for them. All they have to do is click on the link and type in their email address.

[dalai]

If you still check the quarantine folder once a week, do you even need the challenge email? At most it will take a few days longer to reply to a valid email and then you can whitelist the sender.

[BeetleB]

Think of it as "if they respond to the challenge email it'll get in front of my eyes quicker".

Also, keep in mind when I wrote it, I was getting 20-50 spam a day (not counting unsubscribe emails). And part of the motivation was that legitimate emails were simply getting lost (I wouldn't notice them in the sea of noise). Checking once a week would mean scanning hundreds of emails for the few legitimate ones. The challenge-response is more reliable.

(Today I get almost no spam - someone fixed a broken pipe on the Internet).