In order to ensure a successful delivery to your recipient(s), you may want to consider taking the following steps to minimize the chances of your email landing in the spam folder.
If you are using Gmail or Office 365, then you can go with Option 1. If you are not using Gmail or Office 365, then please see Option 2.
Send through External Email Services
1. Go to Setup
2. Search for Email in the Quick Find Search Bar
3. Select Send through External Email Services
4. Enable the option for Gmail or Office 365
5. Additional steps for end users are detailed here
Disable Email Security Compliance & Bounce Management
1. Go to Setup
2. Search for "Deliverability" in the Quick Find Search Bar
3. Select "Deliverability" underneath the Email section
4. Disable "Activate bounce management"
5. Disable "Enable compliance with standard email security mechanisms"
Setup Email Relay
Email relay automatically routes Salesforce-generated emails through your company’s mail service. An email relay uses an email server to send emails that originated somewhere else.
As the System Administrator, you will need to take the following steps:
1. Submit a Salesforce Support case to enable Email Relay in your org. You will need to provide the following details:
- Organization ID (Not sure how to locate this? This guide will show you how.)
- Your request should state, "Allow email relay enablement".
2. Once the Support agent confirms that Email Relay is enabled, you will then set up Email Relays:
- Go to Setup
- Search for "Email Relays" in the Quick Find Search Bar
- Select "Email Relays"
- Select "Create Email Relay" and you will need to input the following information:
- TLS Setting
- Enable SMTP Auth (and input your credentials)
3. Save. Next, you will need to set up the Email Domain Filter:
- Search for "Email Domain Filters" in the Quick Find Search Bar & select
- Select "Create Email Domain Filters" & input the following:
- Sender Domain
- Recipient Domain
- Email Relay
- Enable Active
Additional Resource: SPAM, security configuration and problems when you send emails from Salesforce
- Salesforce Ben, Salesforce Email Relay: Prevent Your Emails Going to Spam
- Paul B. Fischer - Pardot & Salesforce Consultant, How to Configure Email Relay in Salesforce
- Salesforce Trailhead, Send Email Through Salesforce