How to combat webmail spammers?

[Pugglewuggle]

Do you guys have any recommendations on combatting webmail spammers that signup for accounts just to spam? I know your suggestion will be to have the account disbled by default and then have an admin enable it manually, but this is not an option. We rely on our webmail service for a portion of our revenue (from ads) and users need to be able to use it immediately after signing up so we don't miss out on that revenue.

So you have any other recommendations on how to deal with spammers and limit damage when they do get signed up because it is inevitable that a spammer will get in there every now and then?

Thanks,
JB

[rob]

Well the first thing to do is to ensure that your group settings for the new users have the mail sending limits enabled. A spammer will attempt to send many thousands in a day, a user might send only a few. Any user that requires greater mail sending ability can of course contact you and you move them into a new group. There are also mail sending limits in the SMTP itself but these are overall and may cause more problems than they resolve.

[Pugglewuggle]

Just a suggestion I posted today for other viewers -- Create an optional delay before the account is activated so spammers have to wait and the administrator has a chance to react and delete/disable the account for further review.