Public Groups:

Which consists set of users, can be used to assign sharing rules and records. It can also be used in reports and dashboards.

Create a public group(testing group) with required users, roles and profiles. We have to create a workflow rule to send an email to the public group created.

Select --> Setup --> Administer --> Manage Users --> Public Groups.

Click on new public group, give the group name and select the members who should be included in a public group.

Workflow:

Workflow is used to automate actions like Email, Field update, Outbound message and creating tasks. It works based on rule criteria. It consists of criteria, actions when a record matches the criteria and time dependent actions like triggers. Email alert action sends an email to one or more recipients whom we specify.

Select --> Setup --> Administer --> Build --> Workflow & Approvals --> Email alert.

Create an Email alert as when a particular action is done then the mail should be sent to that assigned particular public group (testing group). By clicking on new email alert, we have to select the required object, email template, recipient type and add the required recipients.

Email templates are predefined in salesforce and we can edit them according to the organization requirement. When we select particular predefined email template or the email template which we edited, user receives the email with the information we provided in the email template. 

Select Account in object, Email template as Sales:New customer email, recipient type as public group and add the public group(testing group) to the recipient. Save the email alert and define email alert rule where an email should be sent to a public group which we have selected as a recipient.

Email alert rule:

Select required object, give the rule name, and rule criteria. When an account(object) is created and billing city(field) equals Hyderabad then an email alert should be sent to that public group. Save the email alert rule and activate it.

Implementation:

Create an account with email alert rule criteria and automatically public group(testing group) users receive the email.

Note:

If the Emails are sent via Workflow rules there is a limit of 1000 emails per day for a standard Salesforce license.