This document must not be leaked outside the company.
When meeting someone from outside the company, please don't forget your business cards.
この情報は社外に漏らしてはいけない。
This information must not be leaked outside the company.
It is forbidden to tell people outside the company the details of the project.
We haven't yet announced the new product information outside the company.
社内 means 'inside the company', the direct opposite of 社外, which means 'outside the company'.
社外(品) refers to third-party aftermarket parts, the direct opposite of 純正(品), which means manufacturer-original parts.
company secret; confidential (outside the company)
external communications; outgoing company messages
outside director; independent director
external auditor; outside company auditor
Compound of 社 (company, shrine) and 外 (outside). The meaning 'outside the company' is a straightforward combination of these elements.