Add footer to emails when you are sending email from Salesforce. We can create and use default footer for single emails or mass emails or for both. Footers are text only and maximum is 32 KB.
Setup > Email Administration > Email Footers
Name: Test Email Footer
Active for single email: Select if you want footer to be available for single email.
Active for mass email: Select if you want footer to be available for mass email.
You can select the options if you want to make footer available for single and mass email.
Email Encoding: Select as desired
Text of Footer: Test Footer
Default footer created.