Enabling the spam filter has the effect of sending text content of received emails to an AI connection for spam analysis. You have the following options for setting the filter:
The recommended model is at least GPT-5 Nano or equivalent. The token usage of a typical mail is about 10,000 tokens, so each spam check will cost hundredths of a cent.
Note that the content will be sent to your AI provider. If you are not using a local AI model of your own, make sure that your public data protection agreement allows for this.