Overview

Are there any drawbacks to how an on-premises Exchange server works specifically with mailboxes if MailEssentials is no longer used?

Information

GFI MailEssentials is not involved in delivering or receiving emails. GFI MailEssentials simply scans the emails that arrive or leave, from your server but it is still the IIS/SMTP which is responsible for making the connections.

Therefore the removal of GFI MailEssentials does not affect the performance of your Microsoft Exchange in any way.