Ok, I've put a couple more roadblocks in their way in an attempt to block them. It might mean a few "real" posts go into moderation for a few days, but that's worth it to avoid filling people's inboxes with Chinese spam.
Not sure these are available with the software but a few spam tools I have used.
1. Require email verification, do not allow multiple usernames with the same email.
2. Cap new posts by new user. E.g. only can post three times in the first day after registering.
3. Add questions about Lr to register. If you cannot answer them, account must be approved by moderator. E.g. like who makes it?
4. English characters only for low post counts. E.g. you have to have so many posts before posting in an alternative character set.
5. Throttle registrations. The third and higher registrations must be approved by mod each day.
should be able to lock out links until a certain number of meaningful post are made. No idea how it's done; but we set 20 post on the forum I moderate . Some still try to get to 20 post with a lot of fast posting; that's when I start my game of deleting as they post. Poor buggers never seem to work out what's happening to their post count . Or I wait until they get to 19 and then hit the ban button
Spammer buster -- LOVE it .
We did restrict links, but then newbies with problems couldn't post screenshots of their problem, so it caused more trouble than the occasional spammer, and the spammers got wise and just posted rubbish for their first few posts.
Let's not make this a bigger issue than it is. The number of spam messages that get through is really very low and then they are usually caught quickly. If you don't want to get them in your email box, then follow these forums in your browser.