and I believe no one wants to become spamming when joining the forum.
That's where you're wrong, buddy
I'm going to estimate that 40% of new members are alt account
You are absolutely correct, most of the new members join the forum for the purpose of getting tokens from the airdrop & bounty campaigns. So when they first joined them did not read all the items in the forum for new people, so I have proposed that the forum send email reminded them from the registration is complete. That helps them a lot and avoid making mistakes while working in the forum.
I think you don't need to remind them if what are the forum rules if they care about forum rules they should read the sticky thread first in beginners & help section where you can read all of newbie needs.
Some people came here on the forum are asking about how they can rank their account and it's obvious that they came here in the forum for bounties not for contributing here in the forum. That is why we're here it's because we want to learn and share our thoughts related to bitcoin and cryptocurrency.
And if they are totally a newbie I know they read some thread first before they ask something. Unlike other members making an alt account and acting as a newbie they're directly posting a thread and then ask for merit, activity or how rank system works. This is mostly a question of alt accounts.
The only thing that you must do for those new members if they don't follow the rules then report them to the moderator and only moderators can remind new users about the forum rules.