To change your email body width for all emails:
- Navigate to Content > Content Settings.
- Click Email in the left sidebar, then scroll down to the Email Size section.
- Set a numerical value in the Email Body Width field.
- Click Save changes.
Please note: this change will be applied to all existing email drafts, as well as any future sends of previously sent or automated emails.
If you'd like to change the width of a particular email, check out this article.