I am an admin for a different forum, and have had bot issues as well. (One time I took a 1-week vacation and came back to 42,000 new, fake accounts. sigh.)
Anyway, here is what I have done. (You probably know most of these, but I will mention them just in case.)
1. Any account submission that has the following fields filled in is deleted:
- ICQ Number
If these 4 are all filled in (along with name/email, etc), there is a high, high probability that it is a spam bot account. In reviewing ~60,000 accounts manually, I have never seen a valid account created with all these 4 field filled in.)
2. URLs in the Signature almost always mean a bot. I always check the URL if it looks vaguely real. If the site connected to the URL IS real, and is NOT a retail site, then I am fine with the account.
Anything going to a blog is usually bad - the text will be fake, etc. (Usually the links on the fake blog page are real - which is the whole point I suppose - get people to click those links.)
3. Bots tend to create accounts in groups. So if I see 2-3 fake accounts from the same domain, I put the domain on the banned list - stopping all accounts that try to use the banned domain from creating accounts.
To ban a whole URL, go to the "Ban Control" area in your admin page, then:
- Go to the section marked something like "Ban one or more email addresses"
- Enter an asterisk and then the URL. So if you wanted, for example, to ban all "GMail.com email addresses" from being usable to create a new account, then you enter "*@gmail.com".
- Click the submit button
4. Here is the most controversial step: I have banned most mainstream email addresses from being used, including:
- *@*.cn (meaning every email address ending in .cn)
I don't really want to lose people who use gmail.com, etc so I also mention, in a "sticky" announcement in 2-3 of the sections of the forums (in technical issues, announcements, and universal topics) that people should not enter an ICQ, and I give clear directions on how to contact me if they find their email address is a disallowed one. Usually I un-ban the domain for a day and then re-ban it. The person has that one day to re-apply for an account (which I make sure to activate).
On a different subject, never, ever put your email address into your forum. :-) I say something like this:
Email me at "XXemailXX", then the "AT symbol",
and then "XXmydomainXX.com".
A person should be smart enough to know that that translated into: XXemailXX@XXmydomainXX.com
Hope something in here helps a little.