To connect your SalesForce account, you will need the following:
A SalesForce Instance URL.
A SalesForce Consumer Key.
A SalesForce Consumer Secret key.
A SalesForce Organization ID.
Get the required Data.
Log in to your SalesForce account.
Create a Connected App
Using the Left Sidebar, click on the Apps → App Manager.
Click on the New Connected App button (top right corner).
Fill out the required information:
Connected App Name
API name
Contact email
Enable the Enable OAuth Settings option.
Add the page URL where the Email Opt-in module is located as the Call Back URL.
From the options list, choose Full Access and click on the Add Icon.
Click the Save button.
Get the Consumer Key and Secret Key
Click the Manage Consumer Details button.
Verify your identity by entering the verification code in your email address.
Take note of your Consumer Key and Consumer Secret.
Get the Organization ID
Open the settings panel by clicking on the gear icon.
Click on the Open Advanced Setup.
From the left sidebar, choose Settings → Company Settings → Company information.
Copy the Salesforce.com Organization ID's value.
Connect Email Opt-in module to SaleForce
Open the Email Opt-in module Settings modal window.
Go to the Content Tab → Email Account.
Select SalesForce from the provider's list.
Click on the Add button.
Fill in the following fields:
Name - It can be anything you want. For example, you can use
my-saleforce
Instance URL - The URL of your Salesforce Account Dashboard (after you have logged in).
Consumer Key - Paste the Consumer Key for the connected App.
Consumer Secret - Paste the Consumer Secret for the connected App.
Organization ID - Paste the Organization ID.
Click on the Submit button.
Choose the SalesForce list you want to use.