Spam protection is a multi-level process. The MODS and settings listed below work for me, but do not stop all spam by any means. As you mentioned, it seems like a person backstage is registering some accounts. It's true. Later, this person returns or has an automated bot, using his credentials to send something to spam. In these cases, your only way to respond. You cannot stop everything.
The first step, as noted in the comments, is to create an approval queue for the first message. In PHPBB 3.0.3, this option has been added.
- Go to admin control panel
- Select the General tab
- On the left side, in the "Card Configuration" section, select "Mail Settings"
- Find the
Enable Queued Posts parameter and set the value to 1
You (or your moderators) will have to approve these posts in order to appear. As soon as this first message is approved, the user will be able to post normally.
The next option includes modifications to the board itself. One such modification is Anti-Spam ACP . This release page lists the following features:
- Akismet Integration
- One click ban
- Stop forum spam integration
- Tray for spam words (for example, the word censor, except that messages from authors with less than X messages require approval if the message contains any words in the list)
- Disabling certain profile fields until X number of messages (either not required or always disabled)
- User flag (allows you to flag a user (and unflag after they have been flagged). After flags are marked, actions performed by that user in their profile, or editing messages or adding messages, will be listed in the log in ACP.)
- Spam journal
- IP search
It also states that it "has the ability to completely stop phpBB3 spam." Take this with a huge chunk of salt. I used it on my board for several years. This definitely reduced the amount of spam I received daily, but it does not stop it completely.
The third option is Advanced Block MOD . This adds a few blacklists to your forum. This allows you to add certain weights to specific blacklists (you choose what you like best), but it has a decent set of default values that I suggest you run with it for a while. It adds Block Log to your ACP. You will quickly see that many bots are blocked with this mod. When I wrote this, I noticed that a new version will appear soon, but it did not go through the PHPBB verification procedure. More information, including screenshots of these features, is here .
Using a combination (or all 3) will significantly reduce the speed of spam on your board. As I said earlier, this will not eliminate it, but it will make it more manageable. Your existing users will not need to do anything with these three changes. New users will have one more step - they will have to wait until their first message is approved. After installation and configuration, the administrator does not need to do anything other than track logs to verify that configuration settings need to be changed.