The differences between business letters and business emails can include several things such as tone and formality, writing style, purpose, destination and security and privacy issues. Despite these distinctions, both business letters and business emails are considered business correspondence.
The rigid format of business letters, which are normally sent on letterhead or high grade paper, automatically makes them more formal than business emails.
Because some communications, such as those concerning legal matters, are more appropriate for business letters than they are for business emails, a greater range of formal-to-informal rhetorical styles applies to business letters than business emails.
A wider range of topics and document types are more appropriate for business letters than business emails.
You always direct business letters to an audience external to the organization. Hardcopy communications sent within an organization are called memorandums or memos. You can send business emails to people within the same organization, to people in a separate organization, to an individual or to any combination thereof.
Security and Privacy
Distribution of business letters to secondary parties tends to involve a limited number of recipients. Business email distribution, on the other hand, often involves many recipients; unless the “bcc” function is used, all recipients can see each others’ email contact information, which can create security and privacy concerns.