Scan-to-email 2 MB size limit for no apparent reason. Suspect it's related to SMTP settings. A Microsoft 365 mailbox is configured on MFP units for scan-to-email. : r/sysadmin
SMTP Relay in Office 365 environment | Part 3#4 - o365info
Solved: Canon IR-ADV C5030 scan to email with office 365 | Experts Exchange
How to setup for Office 365 Scan to Email – Newman Business Solutions