---
schema_version: "1"
id: 428fd47c2527e46fba6554f6d5246c6eddbd6f2b05366ab5dab415ba655423e0
title: Deliverability Fundamentals
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/mktg/264-0-0/mktg_apps_email_delivery_basics.md
canonical_url: https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_delivery_basics.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: c57a3abc06f8c37959f7c6cfb16437bdcfd1e0c7b3eb92ff7523b16f33422354
description: Effective email marketing starts with good deliverability, which means that the messages you send are reliably arriving in recipients' email inboxes. Mailbox providers (MBPs) and spam filters evaluate the emails that you send. Part of an email sender's job is to keep data updated and create relevant content that supports a positive reputation.
products:
  - Marketing
release: "264"
---
# Deliverability Fundamentals

Effective email marketing starts with good deliverability, which means that the messages you send are reliably arriving in recipients' email inboxes. Mailbox providers (MBPs) and spam filters evaluate the emails that you send. Part of an email sender's job is to keep data updated and create relevant content that supports a positive reputation.

![Note](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-mktg-mc_best_practices-264-0-0-production-enus/94d1fff8-9516-4dcc-af2f-ac89333fbaec/images/icon_note.png)

Note This content provides general information for all marketers, instead of describing specific Salesforce products. For product details and instructions, look for Further Reading tables throughout this Help section.

## Concepts

When you send marketing emails with Salesforce marketing tools, you're expected to follow certain rules regarding consent and preference processing.

This table outlines the factors that contribute to your deliverability.

<table class="slds-table slds-table_bordered slds-max-medium-table_stacked slds-m-bottom_small ">
        <colgroup>
          <col>
          <col>
        </colgroup>
        <tbody>
          <tr class="">
            <td class="slds-cell-wrap" style="vertical-align:top;"><a href="https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_reputation_create.htm&amp;release=264.0.0&amp;type=5" title="To increase the likelihood that emails land in inboxes where recipients can engage with them, you need a consistent sending history and a good sending reputation. If a sender lacks these qualities, mailbox providers (MBPs) can slow down or block delivery of messages. Each time that you launch a new brand or start working with a new ESP, always schedule time to &quot;warm up&quot; your reputation by establishing a positive sending history.">Sending Reputation and Warming</a></td>

            <td class="slds-cell-wrap" style="vertical-align:top;">
              <ul>
                <li>Are your sending domains and IP addresses trustworthy?</li>

                <li>Do you have a reliable history of sending relevant messages?</li>

              </ul>
            </td>

          </tr>
          <tr class="">
            <td class="slds-cell-wrap" style="vertical-align:top;"><a href="https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_best_practices_technical.htm&amp;release=264.0.0&amp;type=5" title="Email authentication is like showing your ID to prove that you are who you say you are. Mailbox providers (MBPs) and spam filters check for authentication to verify that your emails come from a legitimate source. Authenticate your emails with DomainKeys Identified Mail (DKIM) and Sender Policy Framework (SPF). Most MBPs, including Gmail and Microsoft, use these methods along with DMARC (Domain Message Authentication Reporting and Conformance), when they evaluate incoming messages.">Authentication</a></td>

            <td class="slds-cell-wrap" style="vertical-align:top;">
              <ul>
                <li>Do your emails come from where they claim to come from?</li>

                <li>What do we do with messages that fail authentication?</li>

              </ul>
            </td>

          </tr>
          <tr class="">
            <td class="slds-cell-wrap" style="vertical-align:top;"><a href="https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_best_practices_hygiene.htm&amp;release=264.0.0&amp;type=5" title="For marketing messages, data quality outperforms quantity. Using outdated or mismatched data can mean that you send emails to users who forgot they opted in or have lost interest. Keeping stale data increases unsubscribes, spam complaints, and erodes trust.">Data Hygiene</a></td>

            <td class="slds-cell-wrap" style="vertical-align:top;">
              <ul>
                <li>Did this recipient consent to receive emails from your business?</li>

                <li>Does this recipient still want to receive emails from you?</li>

              </ul>
            </td>

          </tr>
          <tr class="">
            <td class="slds-cell-wrap" style="vertical-align:top;"><a href="https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_best_practices_msg_quality.htm&amp;release=264.0.0&amp;type=5" title="High-quality emails can bypass spam filters and capture recipient attention. The quality of your messaging is based on system filters and user preferences. Content that passes a spam filter isn't always engaging to users, and vice versa.">Branding and Messaging</a></td>

            <td class="slds-cell-wrap" style="vertical-align:top;">
              <ul>
                <li>Does this message contain suspicious or malicious code?</li>

                <li>Is the content written in an aggressive, abusive, or other inappropriate
                  way?</li>

              </ul>
            </td>

          </tr>
        </tbody>
      </table>

## Definitions

Bounce

A bounced email can’t be delivered. There are two types: soft bounce and hard bounce. Soft bounces are usually temporary, such as when someone has an out of office reply set up, and are retried. A hard bounce can’t be delivered because the email address is invalid or can’t be found.

Email Deliverability

The likelihood of your email reaching a recipient’s inbox.

Email Service Provider (ESP)

A platform that helps businesses send emails to large groups of people. Salesforce Marketing products act as Email Service Providers.

Envelope Domain

The background domain that email servers use to route messages and manage server notifications, such as bounces or spam results. Alternate names include the MailFrom, return-path, or bounce domain. It's typically different from the sending domain that your customers see. For example, a sending domain of em.example.com often pairs with an envelope domain of bounce.em.example.com.

IP Address

A unique ID that identifies the server your emails are sent from, like a return address. IP stands for internet protocol.

Mailbox Provider (MBP)

A consumer service, such as Gmail or Outlook, that supports email addresses and mailboxes. Some practitioners use Mailbox Service Provider (MSP) as a synonym.

Subdomain

A human-readable ID that appears before the primary domain, and which is frequently used for email sending or reply management, such as mail.CompanyA.com

- **[Processing an Email](https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_infrastructure.htm&release=264.0.0&type=5)**  
    A lot happens between clicking Send and an email arriving in someone’s inbox. Salesforce kicks off processes that prepare, build, and deliver your message. The exact sending infrastructure and tooling varies by product, but the overall process is similar for most email sends.
- **[Addressing Delivery and Reputation Issues](https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_best_practices_delivery_issues.htm&release=264.0.0&type=5)**  
    To help you identify and address deliverability and reputation issues, Salesforce provides metrics and reports that help you monitor your messaging performance. We recommend evaluating these metrics every three to six months.
- **[Sending Reputation and Warming](https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_reputation_create.htm&release=264.0.0&type=5)**  
    To increase the likelihood that emails land in inboxes where recipients can engage with them, you need a consistent sending history and a good sending reputation. If a sender lacks these qualities, mailbox providers (MBPs) can slow down or block delivery of messages. Each time that you launch a new brand or start working with a new ESP, always schedule time to "warm up" your reputation by establishing a positive sending history.
- **[Authentication](https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_best_practices_technical.htm&release=264.0.0&type=5)**  
    Email authentication is like showing your ID to prove that you are who you say you are. Mailbox providers (MBPs) and spam filters check for authentication to verify that your emails come from a legitimate source. Authenticate your emails with DomainKeys Identified Mail (DKIM) and Sender Policy Framework (SPF). Most MBPs, including Gmail and Microsoft, use these methods along with DMARC (Domain Message Authentication Reporting and Conformance), when they evaluate incoming messages.
- **[Bounces, Unsubscribes, and Spam Complaints](https://help.salesforce.com/s/articleView?id=mktg.mktg_apps_email_best_practices_data.htm&release=264.0.0&type=5)**  
    Salesforce marketing email reports contain metrics about bounces, unsubscribes, and spam complaints. After you understand the differences among these responses, you can act on the insights that you receive and optimize your email marketing program.