What is Email Deliverability?
Email deliverability is whether your emails reach the inbox or get filtered to spam. Mailbox providers like Gmail, Outlook, and Yahoo decide where your email lands based on your sender reputation, authentication setup, and how recipients engage with your messages.
Most teams confuse deliverability with delivery. Delivery means the email server accepted your message. Deliverability means it actually reached the inbox where people check their mail. You can have a high delivery rate and terrible deliverability if all your emails end up in spam.
Email Delivery vs. Email Deliverability
Email delivery tracks whether the recipient's server accepted your email without bouncing it back. Email deliverability tracks where that email lands after acceptance.
This distinction matters because your dashboard might show strong delivery numbers while your emails sit in spam folders. Teams waste time optimizing the wrong metrics when they only watch delivery rates. Fix deliverability first, then worry about opens and clicks.
Why Email Deliverability Matters for B2B Sales
Bad deliverability kills pipeline. When your outbound sequences hit spam, prospects never see them. When your nurture campaigns disappear, deals stall. When your follow-ups get filtered, meetings don't book.
B2B teams run on email. Prospecting, deal communication, customer onboarding all depend on messages reaching the inbox. If your emails land in spam, you are burning budget on sends that generate zero pipeline.
Impact on Pipeline and Revenue
Spam placement destroys every downstream metric. Opens drop to near zero. Replies disappear. Your SDRs send hundreds of emails that never get read. Your AEs follow up on deals that go dark because their messages never arrived.
For teams running outbound at scale, small deliverability problems compound fast. Send 10,000 emails with poor deliverability and you just wasted your team's time and damaged your domain reputation. This is not an IT problem. It is a revenue problem.
What is a Good Email Deliverability Rate?
Strong senders consistently land in the inbox. If you are seeing significant spam placement, you have a problem worth fixing immediately.
Watch inbox placement rate, not just delivery rate. Most email platforms only show delivery, which hides the real issue. Your emails can be "delivered" and still never get seen because they landed in spam.
What Affects Email Deliverability?
Mailbox providers score your emails based on sender reputation, authentication, content, and list quality. Understanding these factors helps you diagnose problems and fix them at the source.
Sender and Domain Reputation
Your domain carries a reputation score based on your sending history. This score follows you across email platforms. A damaged reputation means your emails get filtered no matter how good your content is.
Three things hurt your reputation fast:
Spam complaints: When recipients mark your emails as spam, providers note it and filter future sends
Low engagement: If people do not open or click your emails, providers assume they do not want them
Erratic sending: Sudden volume spikes look like spam behavior and trigger filters
IP Address Reputation
The IP address sending your email also carries a reputation. Shared IPs tie your reputation to other senders on the same infrastructure. Dedicated IPs give you control but require warm-up before you can send at volume.
High-volume B2B senders should use dedicated IPs. The setup work pays off in better deliverability and full control over your reputation.
Email Content and Engagement Signals
Content affects deliverability two ways. Spam filters scan for trigger patterns like excessive links or suspicious formatting. Recipient engagement tells providers whether people want your emails.
Low engagement trains filters to deprioritize your future sends. If people do not open your emails, providers assume they are unwanted and route them to spam.
List Quality and Hygiene
Sending to invalid addresses, spam traps, or unengaged contacts damages your reputation. Bad data causes bounces. Bounces hurt your reputation. Poor reputation leads to spam placement.
List quality is often the root cause of deliverability problems. Fix your data and most other issues improve.
Set Up Email Authentication
Authentication proves to mailbox providers that you are who you claim to be. Without it, your emails look suspicious. Implement all three protocols together: SPF, DKIM, and DMARC.
SPF (Sender Policy Framework)
SPF is a DNS record listing which mail servers can send email for your domain. It helps receiving servers verify that incoming email actually comes from an authorized source.
SPF alone is not enough. You need DKIM and DMARC working together for full protection.
DKIM (DomainKeys Identified Mail)
DKIM adds a cryptographic signature to your emails. This signature proves the email was not altered in transit and confirms your identity.
DKIM builds trust with mailbox providers by showing your emails are legitimate.
DMARC Implementation
DMARC tells mailbox providers what to do when an email fails SPF or DKIM checks. You set a policy level: p=none monitors without taking action, p=quarantine sends failing emails to spam, or p=reject blocks them entirely.
Start with p=none to monitor results. Once authentication is working, move to stricter policies.
Domain and IP Warm-Up Best Practices
New domains and IPs have no reputation history. Sending high volume immediately triggers spam filters because it looks like spam behavior.
Warm-up means gradually increasing send volume to build a positive reputation. This matters for B2B teams launching new outbound programs or switching email platforms.
Follow this approach:
Start with engaged contacts: Send to people most likely to open and reply first
Increase volume slowly: Ramp up over weeks, not days
Watch your metrics: Monitor for bounce spikes or complaint increases
Stay consistent: Avoid sudden volume changes after warm-up completes
Maintain Clean Email Lists
List hygiene is ongoing work. B2B contact data decays as people change jobs, companies change domains, and emails become invalid. Regular cleaning prevents bounces and protects your reputation.
Email Verification and Validation
Email verification checks if an email address exists and can receive mail. Validation checks format and syntax. Run both before you send.
Your verification process should include:
Syntax validation: Catches typos and formatting errors when contacts enter their email
Domain verification: Confirms the email domain exists and accepts mail
Mailbox verification: Checks if the specific address is active
Remove Inactive Subscribers
Sending to unengaged contacts hurts deliverability. Define what inactive means for your business. Most teams use 90 to 180 days with no opens or clicks.
Try re-engagement first. Send a targeted campaign asking if they still want to hear from you. Remove non-responders. This improves engagement rates and signals to providers that your list is healthy.
Optimize Email Content for Deliverability
Content affects spam filter scoring and recipient engagement. Avoid trigger words, maintain proper text-to-image ratios, personalize your messages, and include a clear unsubscribe option.
Follow these guidelines:
Subject lines: Skip all caps, excessive punctuation, and spam trigger words like "free" or "act now"
Body content: Balance text and HTML, avoid image-only emails
Links: Limit link count, skip URL shorteners and mismatched domains
Personalization: Relevant content drives engagement, which improves deliverability
Unsubscribe link: Make it easy to opt out because complaints hurt more than unsubscribes
Email Deliverability Best Practices for B2B
B2B email has different requirements than B2C. You are reaching business contacts who get hundreds of emails daily. Your approach needs to reflect that reality.
Segment Your Audience
Segmentation improves relevance. Relevant emails get opened. Opens improve deliverability. Sending the same message to everyone is a deliverability risk.
Segment by engagement level to separate recent openers from cold contacts. Segment by buyer stage to send different messages to prospects, active opportunities, and customers. Segment by persona to tailor content for different job functions.
2024 Gmail and Yahoo Sender Requirements
Gmail and Yahoo implemented stricter requirements in 2024. If you send more than 5,000 emails per day, you must meet these standards.
You need SPF, DKIM, and DMARC properly configured and passing. You need one-click unsubscribe working. You need to keep spam complaint rates below published thresholds. You need valid forward and reverse DNS configured.
These requirements apply to sales teams running outbound, not just marketing. If you send volume, you need to comply.
How to Track Email Deliverability
You cannot fix what you do not measure. Track the right metrics and run regular audits to catch problems early.
Key Metrics to Monitor
Different metrics reveal different problems. Track them together for a complete picture.
Metric | What It Measures | What to Watch |
|---|---|---|
Delivery rate | Emails accepted by servers | High, but not enough alone |
Bounce rate | Emails rejected by servers | Keep low |
Spam complaint rate | Recipients marking as spam | Keep minimal |
Open rate | Emails opened | Engagement signal |
Click-through rate | Recipients clicking links | Engagement signal |
Inbox placement rate | Emails in inbox vs. spam | Primary metric |
Conduct an Email Deliverability Audit
Run an audit when metrics decline, before major campaigns, or after infrastructure changes. Check that SPF, DKIM, and DMARC are configured correctly. Confirm your domain and IPs are not blacklisted.
Review sender scores and domain reputation through monitoring tools. Analyze bounce rates and engagement by segment to find problem areas. Test emails against spam filter scoring tools before sending.
Common Email Deliverability Issues and Solutions
B2B senders hit predictable problems. Identifying the right problem leads you to the right fix.
Emails going to spam: Check your authentication setup, review content for spam triggers, verify your sender reputation scores.
High bounce rates: Clean your list immediately, verify emails before sending, check data quality at the source.
Blacklisted domain or IP: Identify which blacklist you are on, follow their removal process, fix the root cause that got you listed.
Declining open rates: Re-evaluate your segmentation, test different subject lines, review send timing.
Sudden deliverability drop: Audit recent changes like new email platforms or volume spikes, check for blacklisting.
Key Takeaways for B2B Email Deliverability
Deliverability is a system, not a single fix. Start with authentication. Implement SPF, DKIM, and DMARC together. They work as a set, not individually.
List quality drives your sender reputation. Invest in data accuracy and regular cleaning. Send to valid, engaged contacts and everything else gets easier.
Engagement matters as much as technical setup. Mailbox providers watch how recipients interact with your emails. Low engagement trains filters to send your future emails to spam.
Monitor continuously, not reactively. B2B senders face unique challenges with cold outreach and rapid contact data decay. Address these with proper warm-up, segmentation, and list hygiene.
Accurate contact data is where good deliverability starts. When you send to the right people with valid emails, your reputation stays healthy and your messages reach the inbox. ZoomInfo helps B2B teams maintain accurate contact data that supports strong deliverability and pipeline generation.
FAQ
How long does it take to warm up a new email domain?
Domain warm-up takes several weeks depending on your target send volume. Start with small batches to your most engaged contacts and gradually increase volume each week while monitoring bounce and complaint rates.
Should you use a shared or dedicated IP address for B2B email?
Use a dedicated IP if you send more than 5,000 emails per day because it gives you full control over your sender reputation. Shared IPs work for lower volume senders but tie your reputation to other senders on the same infrastructure.
What is the difference between a hard bounce and a soft bounce?
A hard bounce means the email address does not exist or the domain is invalid, so remove these addresses immediately. A soft bounce is temporary, like a full inbox or server issue, so retry these addresses before removing them.
How often should you clean your email list?
Clean your email list monthly if you send high volume or quarterly for lower volume sending. Remove hard bounces immediately after each send and suppress unengaged contacts after 90 to 180 days of inactivity.
Can you recover from being blacklisted?
Yes, you can recover from most blacklists by identifying the listing, following the removal process, and fixing the root cause like poor list hygiene or authentication issues. Some blacklists remove you automatically after a period of clean sending behavior.
