Edit email to the Vendor

Hi,

It doesn't seem you're using HikaMarket Multivendor ( www.hikashop.com/hikamarket-multi-vendor.html ) on your website so there is no vendor and no email to vendors when products are purchased.
Are you talking about the email sent to the administrator after the purchase ?
This email is the "payment notification" email sent to the administrator after an order is automatically confirmed by a payment notification received by the payment gateway.
You can edit this email via the menu System>Emails if you have HikaShop Business.
Between the HTML area and the template which you can both modify, you should be able to change the width of the email to adapt it to the size required for your printer.