Yes, you can send documents created through mail merge via email using workflow rules with the help of functions. Read more about creating mail merge templates.
Go to Setup > Automation > Workflow rule.
Click +Create Rule.
In Create New Rule, choose a module from the drop-down list.
Enter Rule Name and Description.
Click Next.
In the Workflow configuration page, select When do you want to execute the rule?
Choose a criteria, if you want the rule to execute for selected records.
In Instant Action, choose Functions.
In Configure Functions, select Write your own.
Enter Function name and Display name.
Click Edit Arguments.
In the Edit Argument window, you can change the function name entered previously.
In Argument Mapping, enter the record ID and email ID and map it with the right field.
Click Save.
Enter the below function.
[
url :"https://zohoapis.com/crm/v2/settings/email_templates/653844000009571031/actions/print_preview?record_id=%22 + dealId
];