Deliverability Frequently Asked Questions

This document is a Q&A reference guide for Salesforce Marketing Cloud's Deliverability Agent, covering common customer questions about email and SMS deliverability. It includes answers on topics like IP address setup (dedicated vs. shared), domain authentication (SPF, DKIM, DMARC), bounce management, spam blocklists, list hygiene best practices, and compliance with bulk sender guidelines from providers like Google, Yahoo, and Microsoft.

Question: Can my account have access to both dedicated and shared IP addresses?

Send volumes dictate whether a sender should reside on shared or dedicated IP space. Customers sending >250k emails/month will benefit from using dedicated IP(s) where they can fully control the sending reputation. Read more here: Marketing Cloud Engagement - Dedicated IP and Shared IP use policy.

Additional resources on IPs: https://help.salesforce.com/s/articleView?id=sf.mc_es_dedicated_ip.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.mc_es_ip_addresses_for_inclusion.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.pardot_admin_find_sending_ip.htm&type=5
Salesforce Core Services - IP Addresses and Domains to Allow

Question: Is my account <account #> using shared or dedicated IP for sending mail?

You can raise a Support case to confirm your exact setup.

Question: Can a single Member ID (MID) have more than 1 Sender Authentication Package (SAP)?

No. An account can only host 1 SAP configuration. Additional Private Domains can be purchased for use as From domains.

Additional details: https://help.salesforce.com/s/articleView?id=sf.mc_es_sap_domain_features.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.mc_es_domain_delegation_or_self_hosting.htm&type=5

Question: Can Sender Authentication Packages (SAPs) be copied across MIDs/accounts?

If the accounts exist in the same stack, this can be accomplished via a Support case. You can determine what stacks accounts reside in using the Trust site for Marketing Cloud Engagement. 

Question: Can a Sender Authentication Package (SAP) domain be used as a Private Domain (authenticated for sending mail)?

Yes, a SAP domain can be used as an authenticated Private Domain, but this should be on a different MID under the Enterprise/tenant where the SAP is configured.

Question: Can I use a domain or subdomain already in use elsewhere for sending?

This requires the customer to have the DNS savvy to accomplish the setup. Salesforce cannot offer guidance/assistance on DNS matters. The most common issue customers experience is conflicting DNS records.

Question: How to change a Sender Authentication Package domain.

Domain changes require the purchase of a new SKU from your Account Executive. If you already have additional SKUs on file, you can contact Support to initiate configuration.

Question: Email Sender Guidelines

In 2024, Google, Yahoo, and Microsoft implemented stricter requirements for bulk email senders. These guidelines include domain authentication, inclusion of a list unsubscribe header and limiting complaints. Marketing Cloud Engagement offers solutions to ensure your mail is compliant with these guidelines.

Additional resources on Email Sender Guidelines:

https://help.salesforce.com/s/articleView?id=sf.mc_es_bulk_sender_guidelines.htm&type=5
Engagement - Bulk Sender Guidelines for marketing Cloud Engagement: Addendum
https://www.salesforce.com/blog/email-authentication/
https://mcmoments.hubs.vidyard.com/watch/a9eWg7wZm2GBGuj3ysbUEL

Question: Can Salesforce call an ISP/Mailbox Provider and tell them to inbox a customer's mail?

No. ISP/Mailbox Providers are in the business of keeping their users happy, not email senders. They use sophisticated algorithms to determine if mail from a sender is wanted by their users (tracking statistics around opens rates and clicks as positive and complaints and bounces as negative). Only by doing all the right things as a sender (focus on engaged subscribers, sending relevant content at an agreed-upon frequency, avoiding old list segments that may mark mail as spam or contain converted spam trap addresses) can a sender influence their ability to reach the inbox.

Additional details: https://mcmoments.hubs.vidyard.com/watch/qwFwP6gjFWZeB6o65K4pxi

Question: Do I need to warm my new IP/domain?

Yes, this is the most important step a sender can take to establish a positive sending reputation. More details on warming a new sending IP or domain can be found here: https://help.salesforce.com/s/articleView?id=sf.mc_es_ip_address_warming.htm&type=5

Question: What are options for assistance with ongoing deliverability monitoring/services?

Your Account Executive can help you with details of a paid engagement with our Professional Services team.

Question: Holiday guidance. Cyber Week guidance.

 https://www.salesforce.com/blog/email-deliverability-readiness-peak-volume/

Additional Resources:

Marketing Cloud Engagement: Holiday Readiness Best Practices for Email Deliverability, Journey Builder, and API Performance
https://www.salesforce.com/blog/cyber-week-impact/

Question: B2B email sending.

B2B email marketing has its own unique set of challenges for companies trying to market their products and services to other companies. The prevalence of inbound filtering, non-human interactions, such as inflated bot clicks and even the subscriber opt-in process can vary greatly from the B2C space. Read more here: https://www.salesforce.com/blog/b2b-email-marketing-best-practices/

Question: Bot clicks. Inflated opens or clicks.

Open and click rates remain common KPIs in email marketing, but the prevalence of inbound mail filtering at major mailbox providers. These filters are known to scan/open emails including all links to ensure there isn’t malicious content in the message. Marketers must learn to use these metrics as directional indicators. More input from members of our Trailblazer Community can be found here: https://www.salesforce.com/blog/email-engagement/

Additional details: Engagement - Filter anti-spam software clicks and clickbots from Marketing Cloud Engagement Tracking Data

Question: Can I send to purchased data? Bought a list.

The Salesforce anti-spam policy requires that our customers obtain explicit consent in order to engage a contact from our platform. You can read more about opt-in best practices here: https://www.salesforce.com/marketing/email/opt-in/

Question: Deliverability best practices. Tips to improve delivery.

Nurturing an ongoing relationship between you and your email recipients is crucial for great marketing. Maintaining high email deliverability is crucial because it directly influences your chances for higher customer engagement – not to mention it lends itself to favorable sender reputation opens in a new window over time. The main objectives of good email deliverability is to reach the inbox by minimizing spam flags, reducing bounce rates, and effectively managing complaints. A deeper dive into best practices can be found here: https://www.salesforce.com/marketing/email/deliverability/

Additional details: https://trailhead.salesforce.com/content/learn/modules/email-deliverability-essentials
https://help.salesforce.com/s/articleView?id=sf.mc_es_email_deliverability.htm&type=5

Question: High volume one-time send? Accommodate a large volume of mail.

Salesforce Marketing Cloud shared IP space is reserved exclusively for low-volume senders (<250k/month) and pre-warmed IPs are not available on our platform. Customers who need to send high volumes of mail, even in one-time scenarios, will need to ensure they have enough dedicated IP space in place to do so. Dedicated IP skus can be purchased from your Account Executive and must be warmed to build reputation prior to high-volume sends being conducted. More on IP warming can be found here: https://help.salesforce.com/s/articleView?id=mktg.mc_es_ip_address_warming.htm&type=5

Question: My emails are bouncing due to DMARC when I send from my purchased private domain. How can I resolve this issue?

Typically this requires the enablement of a feature called ‘multi bounce domain’ on your MID. This will result in your ‘from domain’ matching with your ‘bounce domain’. This is a requirement for DKIM and DMARC alignment. Please open a Support case for assistance with enabling this feature.

Question: Our mail is bouncing. Bounces at mailbox providers.

Bounces are often an indicator of issues with your data or perception of the content being sent. A focus on engaged subscribers with recent clicks/conversions and ensuring content is personalized to drive further engagement helps prevent blocking/bounce issues from occurring. More information on common types/causes of bounces can be found here: Engagement - Bounce categories and reasons for Marketing Cloud Engagement email sends.

Additional details: https://help.salesforce.com/s/articleView?id=sf.mc_es_bounce_mail_management.htm&type=5
Engagement - How to Review Marketing Cloud Engagement Bound Data using Automation Studio
Engagement - Bounces in Marketing Cloud Engagement

Question: Monitoring deliverability in Marketing Cloud Engagement. Better Monitoring solutions.

Looking for a way ‌to track your key deliverability metrics over time to better understand trends and how mailbox providers view your reputation as a sender?

You can find the details of how to utilize existing products inside Marketing Cloud Engagement to build your own deliverability monitoring dashboard here.

Question: SURBL blocklist.

Definitions of Spam URI Realtime Blocklist (SURB) lists and delisting instructions can be found here: https://www.surbl.org/lists

The delist process starts with a lookup of the sending IP(s) here: https://www.surbl.org/surbl-analysis

Question: Why am I getting blocks for Chinese domain(s)? Mailing to China.

Deliverability to China is notoriously difficult unless you have email servers in China. Currently, there's nothing we can do to improve deliverability to Chinese domains and we have no path for mitigation.

The best recommendation we can suggest is that the customer segments their sends to Chinese domains and do a sort of warming process. Start with a very low number of sends (e.g. 10/day) to these Chinese domains per day and slowly build to see if they're able to get messages through without being blocked.

Below is a link to the help doc on Email Delivery in China:

https://help.salesforce.com/s/articleView?id=sf.mc_es_email_deliverability_in_china.htm&type=5

Question: Google Postmaster Tools

If you are looking for additional information from Gmail, you can register your Marketing Cloud domain with Google's Postmaster Tools to receive additional panel data back from the ISP.  For more information, see Google Postmaster Tools enrollment for Marketing Cloud Domains. 

Question: SNDS access for Microsoft’s postmaster site.

The Microsoft Hotmail and Outlook SNDS (Smart Network Data Services) interface can aid deliverability troubleshooting, providing a color-coded (Red, Yellow, Green) reputation overview and aggregate statistics relating to spam complaints and spam trap hits. Microsoft SNDS is a free service offered by Microsoft  For more information, see Engagement - Request Microsoft SNDS access for dedicated IPs.

Question: SSL setup.

Secure Socket Layer (SSL) certificate to improve the security of your page-based interactions. Give your subscribers and contacts more confidence when they visit pages that you host with Marketing Cloud Engagement. A certificate adds a layer of encryption to the transfer of sensitive or personal information. This encryption helps prevent external parties from accessing information sent to or from your contacts.

Marketing admins can secure custom domains that are either delegated to Salesforce (DNS Status is Delegated) or self-hosted (DNS Status is Self-Hosted).

Additional details: Marketing Cloud Engagement SSL Certificates Overview
SSL Certificates for Custom Domain Security

Question: What is opt-in/permission based marketing?

Give your customers the chance to sign up, or “opt in,” you’re asking for their consent — a sign of respect. When you ask for permission to send a customer your marketing messaging, you’ll usually find a more receptive audience. Visit the Opt-In Email Strategies page for more information.

Additional details: https://www.salesforce.com/products/marketing-cloud/sfmc/marketing-cloud-anti-spam-policy/
https://www.salesforce.com/company/legal/abuse/

Question: Trailhead/training for deliverability.

Trailhead: https://trailhead.salesforce.com/content/learn/modules/email-deliverability-essentials

Recorded Training on Authentication: Understanding the Gmail/Yahoo Sender Guidelines

Recorded Training on Subscriber/List Hygiene: List Hygiene

Deliverability (Complete Guide) Blog: https://www.salesforce.com/marketing/email/deliverability/

Question: List cleaning/validation services.

https://appexchange.salesforce.com/appxSearchKeywordResults?keywords=list%20validation

Question: Volume on an IP. Capacity of a single IP address. Volume per day.

Mailbox providers limit the amount of mail an IP address can send in a day. This is not a Marketing Cloud restriction but is tied closely to how mailbox providers view your reputation as a sender. Sending large amounts of mail through a single IP address can appear as 'spammy' behavior to many mailbox providers.

Where we start seeing deferrals from major mailbox providers occur is typically once a customer starts sending 2M+ emails per day through a single fully warmed IP. The customer should add more IPs if they’re wanting to send more than 2M emails per day.

3 key points to keep in mind:

• 1 Dedicated IP can send a maximum of 2.5M million sends per day (24 hour window), once you reach 2M sends per day it's time to start adding IP capacity for your campaigns.

• Project ahead for growth; if you’re going to need more IP(s) to accommodate volume in the next 1-3 months, add them now. New IPs will require an IP warm-up plan.

• Mailbox providers are on high alert Oct. - Dec. as mail volume spikes due to the retail season (Cyber Week). Learn more about how Cyber Week volume impacts a sender's reputation in this blog.

Remember that deliverability success is reflective of sending practices. If you are sending more than the recommended volume and seeing a decrease in deliverability or an increase in deferrals, it may be time to review your email program and IP configuration.

Question: Hazards of list/contact/email purchasing. List sharing. Co-registration.

While buying lists might seem like a quick way to grow your audience, it can lead to significant problems. Here's why:

The Hazards of List Purchasing

1. Compliance and Legal Risks

Purchasing email lists often violates privacy laws like:

GDPR in the EU

CAN-SPAM Act in the U.S.

CCPA in California

Non-compliance can result in hefty fines and penalties.

1. Poor Data Quality: Purchased lists are often filled with outdated or inaccurate data, leading to high bounce rates and low engagement. This diminishes the effectiveness of campaigns and skews your analytics in SFMC.

2. Negative Impact on Deliverability: Recipients who didn’t opt-in are likely to unsubscribe or report your emails as spam, harming your sender reputation and decreasing deliverability rates.

3. Brand Reputation Risks: Sending unsolicited emails can damage your brand’s image. If your emails are seen as intrusive, it can foster negative perceptions that are hard to reverse.

4. Ineffective Segmentation: Purchased lists lack proper segmentation, making it difficult to deliver personalized content. SFMC's powerful segmentation tools work best with quality, permission-based data.

5. Resource Drain: The time spent fixing issues from poor-quality lists—such as handling compliance problems and cleaning data—can far exceed any short-term gains.

6. Missed Engagement Opportunities: Relying on purchased lists distracts from nurturing your existing, engaged audience, which could lead to deeper customer relationships and better long-term results.

Question: Feedback Loops

Mailbox provider feedback loops (FBLs) are mechanisms that allow ISP users (end subscribers) to click on the “report spam” or “this is spam” button in their email client, which tells their ISP that they find a given email message to be unwanted.

After an end-subscriber clicks on the “report spam” or “this is spam” button in the user interface of a given email client, an “FBL complaint” is sent back to Salesforce Marketing Cloud for processing. Upon receipt of this FBL complaint, the recipient who lodged the complaint will be unsubscribed from mailings from that client. The complaint is logged and the recipient will show up in send stats as a complaint and as an unsubscribe. More details: ISP Feedback Loops for Marketing Cloud.

Question: Spamhaus related blocking. Spamhaus listing.

Spamhaus is one of, if not the largest third party spam monitoring platforms in existence. A listing at Spamhaus can impact the ability to deliver mail to large portions of your audience. Services like Spamhaus gather data points from a number of mailbox providers, including the number of complaints registered against your mail and how many spamtraps are found in your audience.

Avoiding listings at Spamhaus (or other third-party spam filtering services) requires following the  list hygiene best practices of sending relevant content to engaged subscribers who opted in to hear from your company. Avoiding bad practices such as list-purchasing/appending, sending to unengaged subscribers >6+ months or spreading volume over a large number of sending IPs/different ESPs. If you are seeing bounces mentioning Spamhaus, stop sending and begin a deep-dive review of your recent campaigns to determine what changed. Isolating the issue and resolving it is often a requirement to get de-listed from Spamhaus. Once you have an idea of what is needed to resolve the listing, open a ticket with our Support team, who can help in engaging Spamhaus on your behalf.

More helpful FAQs from Spamhaus: https://www.spamhaus.org/faqs/marketing-email/

Question: Do links in SMS impact delivery?

Due to increasing incidents of smishing and fraudulent communications, regulators and carriers in certain markets are restricting the use of web links in message content. In some markets, use of shortened URLs using services like bit.ly, cutt.ly or tinyurl are not allowed and messages containing them will be blocked. In other markets, URLs must be registered and allowlisted before message deployment.

Question: Can I track bounces for SMS campaigns?

Like email bounces, MobileConnect offers insight on message status via 'delivery receipts' (DLRs).

Standard reports in MobileConnect simplify delivery with either a delivered or undelivered status. To see the full suite of DLRs, refer to SMS Status Codes.

DLRs are slightly different for each global carrier. Engagement consolidates them in standard status codes to allow for universal reporting of SMS delivery.

You can also see DLRs using the SMSMessageTracking Data View and this API call.

Question: SMS delivery best practices.

Although SMS has a high delivery rate, delivery of an SMS message (much like email) depends on following best practices when sending to a particular market or region. For country-specific guidance, consult the MobileConnect Guides for SMS Sending.

Question: When importing a subscriber, we receive an error that states "Your SPAM filter does not allow this email address and cannot be added".

This is due to the email address, username or domain being part of our List Detective feature. List Detective is a proprietary Marketing Cloud database of domains and usernames that your Lists are "scrubbed" against whenever they're imported. The database includes known email spam traps, blocklist addresses, wireless domains, retired (no longer active) email companies or webmail providers, global unsubscribes, and mistypes.

If you would like to import a filtered username or domain or discuss why it is included on this list, please contact our Support team.

Question: Does Salesforce Marketing Cloud meet Sender Guidelines requirements?

Marketing Cloud provides the necessary tools for a sender to comply with Sender Guidelines. Mail sent from Marketing Cloud contains a list unsubscribe header mechanism, complaints are processed in real-time and authentication solutions such as Sender Authentication Package and Private Domain allow customers to authenticate domains with SPF, DKIM and DMARC. Read more on Sender Guidelines here: Engagement - Bulk Sender Guidelines for Marketing Cloud Engagement: Addedum.

Additional Information: https://help.salesforce.com/s/articleView?id=mktg.mc_es_bulk_sender_guidelines.htm&type=5
Email authentication Just got More Crucial: Here’s Why

Question: Is Domain Warming required when sending on the shared pool?

Yes, domain warming is required. Domain reputation has become as important as IP reputation when it comes to the major mailbox providers. Even though your account is on a shared pool, your domain reputation is still taken into consideration as well when mailbox providers determine how to treat your email sends. When sending from a new domain, the chance for the best success is to warm it by, preferably focusing on recently opted-in recipients and those who have engaged in the past 90-180 days. Mailbox providers want to see engagement by recipients who receive email from that new domain.