Spam check before forward

Hi,
my employee use forward email, but some emails not come to tham.

I suppose, that problem is on Spam check, but when I read forum i find:

https://help.zoho.com/portal/en/community/topic/most-of-my-mail-is-not-forwarded-to-my-new-address
- Even if you switch off the Spam filters, the spam emails will not be auto-forwarded to the other accounts.

Is it true?

Is there chance to forward all emails(SPAM included)?