Greetings Schimon,
Thank you for raising this.
I'm concerned that moderating all first-time posters may be worse than the problem it aims to solve. Reviewing the archives, there appear to be only six or seven spam messages in the past year, though admittedly several were recent.
There's a balance to strike between preventing spam and remaining welcoming to new contributors. At present, I'm not convinced stronger moderation would be beneficial, though it's something we should continue to monitor.
Kind regards,
Guus