I have the same number of mailboxes on Google Workspace and PMTA configured. For PMTA mailboxes, all necessary settings have been taken into account and their IP reputation is higher than that of Google Workspace. However, PMTA mailboxes are much more likely to end up in spam, and Google Workspace mailboxes receive 2x more replies. Why do mailboxes on Google Workspace work better than mailboxes configured on PMTA?

For PMTA, I made all the settings correctly. Many services indicate the high reputation of the IP and the correct DNS settings. I would like to know what is the reason that mailboxes on Google Workspace have higher deliverability, although their IP reputation is low.