(1) Segmail doesn't require wide-spread adoption in order to be effective.

(2) Further, depending on how you use email, it may not be the right solution for you (compare the advantages versus the disadvantages) - and that is okay because see point 1.

Mailing lists and other legitimate email uses would be affected

A mailing list is just another correspondant. You supply your email address, they send you mail at that address, it goes through as normal. I am unclear how they would be affected.

It is defenseless against brute force attacks

The fact that the email address contains an eight character random password means that they are defended against dictionary attacks. Certainly better defended than a non-segmail address is. Define a brute force attack.

It will stop spam for two weeks and then we'll be stuck with it

Stuck with what? The system or more spam? If one address is compramised it can be rotated without effecting the rest of your correspondants.

Users of email will not put up with it

Not all users of email are required to put up with it. It works whether or not everybody uses it. For the correspondants of a Segmail user, it is simply a normal address change. What's to put up with?

Many email users cannot afford to lose business or alienate potential employers

Once again, it is simply a one-time address change. I don't see how it effects them.

Spammers don't care about invalid addresses in their lists

Therefore what? This statement is irrelevant.

Ease of searching tiny alphanumeric address space of all email addresses

This is a stated disadvantage - and for some users of email, may be worth the tradeoff.

Why should we have to trust you and your servers?

You don't. Run it on your own server. It is a decentralized solution requiring no centralized authority in order for it to work.

Temporary/one-time email addresses are cumbersome

This is a stated disadvantage - and for some users of email, may be worth the tradeoff.

-Andrew.