Sending attractive, branded emails from your store is a nice touch, not only does it reinforce your presence with your customers, it puts you on the same level as other eCommerce big wigs. Follow the directions below to send html emails from you Zen Cart store.

1. Go to Configuration -> Email Options
Set "Use MIME HTML When Sending Emails" (3rd line) to true
and
Set "Email Admin Format?" to HTML (line 10)

2. Go to Configuration -> Customer Details
Set "Customer Default Email Preference" (line 10) to 1 for html

3. Upload your store logo, saved as header.jpg to email/ folder on the server (you will be overwriting the default zen cart logo)

4. Language File Changes:
Change the define for EMAIL_FOOTER_COPYRIGHT to link back to your store in:
admin/includes/languages/english/email_extras.php
and
includes/languages/english/email_extras.php

5. The design for each email is defined in style section of the header for each of the following email template files:
email/email_template_checkout.html
email/email_template_contact_us.html
email/email_template_coupon.html
email/email_template_default.html
email/email_template_direct_email.html
email/email_template_gv_mail.html
email/email_template_gv_queue.html
email/email_template_gv_send.html
email/email_template_low_stock.html
email/email_template_newsletters.html
email/email_template_order_status.html
email/email_template_password_forgotten.html
email/email_template_product_notification.html
email/email_template_product_notification.html

Change the css in each file or create a external stylesheet and link to it from the header of each file.

6.You can check your changes in Tools -> Email Welcome of your admin. When you have finalized the design, sign up as a new customer on your web site, you should get a branded email generated from zen cart.