Yahoo's disposable addresses are constructed in that form (basename-keyword@yahoo.com), but I'm not sure if they support them on business/custom domain accounts

Yahoo's disposable addresses are constructed in that form (basename-keyword@yahoo.com), but I'm not sure if they support them on business/custom domain accounts. (The base name also has to be different from your real email address, but that's a fairly desirable feature for disposable addresses since it doesn't reveal the real address like the '+' suffix on Gmail does.)