Email Template Allocations Per Edition

See the allocations for email and email templates per edition.

Feature	Personal Edition	Contact Manager	Group Edition	Professional Edition	Enterprise Edition	Unlimited and Performance Edition	Developer Edition
Email templates: maximum size	384 KB for text email templates	384 KB for text, HTML, and custom HTML Classic templates; Lightning templates, and Email Template Builder templates 1 MB for Visualforce templates
Extended mail merge: maximum records	1,000
Extended mail merge: maximum total size of selected templates	1 MB