Email Security.cloud email size discrepancies

Products

• Email Security.cloud

Issue/Introduction

The report on the mail server shows different email size than in the Email Security.cloud.

Environment

Email Security.cloud

Cause

.msg to .eml conversion changes email size

Resolution

Multiple mail servers use .msg as a file format for emails. When an email is sent from it to Email Security.cloud it is converted to .eml format for SMTP, so the conversion changes the size of the file. The difference in sizes is specially prevalent if there are any attachments.
The .msg to .eml conversion encapsulate the attachments in MIME format, which usually results in bigger file sizes.