In Salesforce, one can efficiently resolve customer inquiries via email. Salesforce automatically creates a case when an email is sent to one of your salesforce organizations. Customer responses regarding a case are automatically associated with original case, including the attachments customer sends. We can set up Email-to-Case or On-Demand Email-to-Case to resolve customer inquiries via email. Organization allows you to select any one of those two.

Email-to-Case:

To implement Email-to-Case, first we should download Email-to-case agent and set it up in your local machine(i.e in network firewall). In this, you can accept email attachments larger than 25 MB from customers

Setup:

Click on Setup --> Customize --> Cases --> Email-to-Case 

In the Email-to-Case settings, click on edit and select the settings based on your organization requirement.

Each routing address is an email address that your customer uses to submit cases to the support team. So, select the routing address and click on save.

Emails are automatically converted into cases based on the settings provided in routing address. We can change existing routing addresses with another address by verifying them.

Now you need to download the Email-to-Case Agent and configure it to run against your email server.

Note:

The Automated Case User whom you select in Setup --> Customize --> Cases --> Support Settings will receive an error notification every time the Email-to-case agent fails to create a case.

On-Demand Email-to-Case:

It automates the conversion of emails to cases without any Email-to-Case agent installation. Whenever customers send messages to email addresses which you specify, Salesforce creates cases and auto-populates case fields. It doesn't accept the cases which have attachments more than 25 MB size.

Setup:

Click on Setup --> Customize --> Cases --> Email-to-Case.

Enable and configure On-Demand Email-to-Case and configure routing address settings.

Cases are created based on the settings provided in routing address.

Test the routing mail address by manually sending the emails and see whether they are converted into cases or not.

Note:

The Automated Case User whom you select in Setup --> Customize --> Cases --> Support Settings will receive an error notification every time when an On-Demand Email-to-case fails to create a case.