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Email deliverability determines whether your emails land in the inbox, the spam folder, or bounce entirely. This guide covers everything you need to set up, monitor, and optimize email sending from the HoopAI platform.

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Why deliverability matters

Every email you send has one of three outcomes: A healthy sender should maintain:
  • Inbox placement rate: 95%+
  • Bounce rate: under 2%
  • Spam complaint rate: under 0.1% (1 per 1,000 emails)

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Dedicated sending domain setup

Setting up a dedicated sending domain is the single most important step for email deliverability. Without it, your emails are sent from a shared domain, which means your reputation is affected by other senders.

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Adding a domain

1

Navigate to email settings

Go to Settings > Email Services in your account.
2

Click Add Domain

Click Add Sending Domain and enter your domain name (e.g., mail.yourbusiness.com). Using a subdomain like mail. or send. is recommended to protect your root domain’s reputation.
3

Add DNS records

The platform will generate DNS records that you must add to your domain’s DNS provider (GoDaddy, Cloudflare, Namecheap, etc.). You will need to add SPF, DKIM, and DMARC records.
Email settings showing required SPF, DKIM, and DMARC DNS records to add

DNS records generated for email domain authentication

4

Verify DNS records

After adding the records, click Verify in the platform. DNS propagation can take up to 48 hours, but typically completes within 1-4 hours.

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SPF record

SPF (Sender Policy Framework) tells receiving mail servers which servers are authorized to send email on behalf of your domain.
You can only have one SPF record per domain. If you already have an SPF record, you must merge the new include: directive into your existing record rather than creating a second one.

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DKIM record

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to your emails, proving they were not tampered with in transit.

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DMARC policy

DMARC (Domain-based Message Authentication, Reporting, and Conformance) tells receiving servers what to do if SPF or DKIM checks fail. DMARC policy options:
Start with p=none for at least 2-4 weeks while monitoring DMARC reports. Only move to p=quarantine or p=reject once you are confident all legitimate email is properly authenticated.

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DNS verification checklist

Use this checklist to confirm your email authentication is complete:

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Email warmup

When you set up a new sending domain, mailbox providers (Gmail, Outlook, Yahoo) have no history with your domain. Sending a large volume of email immediately will trigger spam filters. Email warmup is the process of gradually increasing your sending volume to build a positive sender reputation.

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How it works

During warmup, the HoopAI platform sends emails between real inboxes in a managed network. These emails are opened, replied to, and removed from spam — all signals that tell inbox providers your domain is trustworthy.
The built-in warmup feature is available with HoopAI Email. If you use Mailgun or a third-party SMTP provider, you will need to manage warmup manually or use an external warmup service.
If at any point during warmup your bounce rate exceeds 2% or spam complaints exceed 0.1%, stop sending immediately, clean your list, and resume at a lower volume.

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Enable warmup

1

Go to Email Services

Navigate to Settings > Email Services and select your sending domain.
2

Turn on warmup

Toggle the Email Warmup switch to enabled. The platform will begin sending warmup emails automatically.
3

Monitor progress

Check the warmup dashboard daily to track inbox placement rates and warmup email interactions.
4

Gradually send real campaigns

As warmup progresses, begin blending in your real campaign emails while staying within the daily limits above.

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Warmup best practices

  • Send to your most engaged contacts first — people who have recently opened or clicked your emails
  • Avoid purchased or scraped lists during warmup — these have high bounce and complaint rates
  • Use real, valuable content — not test emails or placeholder content
  • Monitor daily — check bounce rates, complaint rates, and open rates after each send
  • Do not skip warmup or ramp too quickly — a sudden spike in volume from a new domain is a classic spam signal and can result in your domain being blacklisted

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Sender reputation

Your sender reputation is a score assigned by mailbox providers based on your sending behavior. It determines whether your emails reach the inbox.

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Factors that affect reputation

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Monitoring reputation

  • Google Postmaster Tools — free tool to monitor your domain reputation with Gmail. Set up at postmaster.google.com
  • Microsoft SNDS — monitor reputation with Outlook/Hotmail
  • MXToolbox — check for blacklists at mxtoolbox.com/blacklists.aspx
  • Platform analytics — check email stats in Reporting > Email in the HoopAI dashboard
Set up a weekly review of your email metrics. Catching a deliverability dip early — before it triggers a blacklist — is far easier than recovering from one.

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Email service providers

The HoopAI platform supports three email sending methods:
HoopAI Email is the built-in email service.

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HoopAI Email pricing

HoopAI Email uses a simple usage-based pricing model with volume discounts.
Pricing is subject to change. Check Settings > Email Services > Billing for your current rates and usage.

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Email bounces

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Hard bounces vs soft bounces

The platform automatically handles bounces:
  • Hard bounces — contact is marked as bounced and excluded from future sends
  • Soft bounces — retried automatically; marked as bounced after multiple failures

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Bounce rate management

To keep your bounce rate under 2%:
  1. Validate emails before importing — use email verification services to clean lists
  2. Remove inactive contacts — contacts who have not engaged in 6+ months are more likely to bounce
  3. Use double opt-in — require email confirmation before adding to your list
  4. Never use purchased lists — these have extremely high bounce rates
  5. Check for typo domains — gamil.com, yahooo.com, hotmal.com, etc.

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Spam complaints

A spam complaint occurs when a recipient clicks “Report Spam” or “Mark as Junk” in their email client.

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How to minimize spam complaints

  • Only email people who opted in — this is the #1 way to prevent complaints
  • Include a clear unsubscribe link — make it easy and immediate (do not require login)
  • Set expectations at opt-in — tell people what they will receive and how often
  • Honor unsubscribes immediately — process within 24 hours (legally required within 10 days under CAN-SPAM)
  • Use a recognizable “From” name — recipients should immediately know who is emailing them
  • Send relevant content — irrelevant emails get marked as spam even from opted-in contacts
  • Maintain consistent sending frequency — sudden spikes look suspicious

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List hygiene

Regular list maintenance is critical for deliverability:

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Monitoring email performance

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Where to check email stats

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Key metrics to monitor

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Common issues and fixes

Check these in order:
  1. Email authentication — verify SPF, DKIM, and DMARC are all passing. Use mail-tester.com for a quick test
  2. Sender reputation — check Google Postmaster Tools for domain reputation
  3. Content — avoid spam trigger words (FREE, ACT NOW, LIMITED TIME), excessive capitalization, too many links, or image-only emails
  4. Text-to-image ratio — emails that are mostly images with little text are flagged more often
  5. List quality — high bounce or complaint rates damage reputation
  6. Warmup — if your domain is new, you may be sending too much too soon
  7. Unsubscribe link — ensure every email has a visible, working unsubscribe link
  8. Plain-text version — include a plain-text fallback to improve trust signals
Possible causes and fixes:
  • Subject lines — test different subject lines with A/B splits; keep them under 50 characters; personalize with contact name
  • Sender name — use a recognizable name, not “noreply@”
  • Send time — test different days and times; Tuesday-Thursday 9-11 AM tends to perform best
  • List engagement — segment by engagement; stop sending to contacts who never open
  • Inbox placement — your emails may be going to spam (see above)
  • Preview text — customize the preview text that appears after the subject line
  • Promotions tab — Gmail may be placing your emails in the Promotions tab rather than Primary
Immediate actions:
  1. Stop sending until you clean your list
  2. Remove all hard-bounced addresses
  3. Run your list through an email verification service
  4. Remove contacts who have not engaged in 6+ months
  5. Check for typo domains (gamil.com, yahooo.com, etc.)
  6. If importing a new list, verify before importing
  7. Never import purchased or scraped email lists
Troubleshooting steps:
  1. Wait at least 1-4 hours for DNS propagation
  2. Verify you added records to the correct domain/subdomain
  3. Check for copy-paste errors in the record value
  4. Ensure you do not have duplicate or conflicting records (especially multiple SPF records)
  5. Use nslookup or MXToolbox to verify records are published
  6. If using Cloudflare, ensure the DNS record is set to DNS Only (gray cloud), not proxied
Check:
  1. Email service is connected and active (Settings > Email Services)
  2. Sending domain is verified
  3. Account is in good standing (no suspensions)
  4. Daily sending limit has not been reached
  5. Contact has a valid email address and is not marked as bounced or unsubscribed
  6. Check billing — insufficient balance may pause sending
Steps to resolve:
  1. Identify the blacklist using MXToolbox Blacklist Check
  2. Fix the root cause — high bounce rates, spam complaints, or compromised sending
  3. Submit a delisting request through the blacklist’s self-service removal process
  4. Re-warm your domain — treat it as partially new, ramp volume gradually over 2-3 weeks
Troubleshooting:
  • Verify that your SPF record includes the correct include: value for your sending service
  • Confirm that DKIM is properly signed — check the d= and s= values in email headers match your DNS records
  • Start with p=none to collect reports before enforcing p=quarantine or p=reject
  • Use a DMARC analyzer tool to review your DMARC reports and identify failing sources

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Best practices by email type

Cold email has the highest risk of deliverability problems. Use a dedicated subdomain (e.g., outreach.yourdomain.com) so that reputation damage does not affect your main domain. Never send cold email from your primary business domain.

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Frequently asked questions

Plan for 4-8 weeks of gradual warmup. The exact timeline depends on your target volume and how engaged your recipient list is. Rushing warmup is one of the most common deliverability mistakes.
Yes. Using a subdomain like mail.yourdomain.com or send.yourdomain.com protects your root domain’s reputation. If your sending subdomain gets a poor reputation, it does not affect email sent from your root domain (like employee email).
A spam trap is an email address used by mailbox providers and anti-spam organizations to catch senders using bad practices. There are two types: pristine (never belonged to a real person) and recycled (abandoned addresses repurposed as traps). Hitting a spam trap severely damages your reputation.
Not recommended. Personal email accounts have very low sending limits (500/day for Gmail, 300/day for Outlook) and are not designed for bulk or automated sending. Use a dedicated sending domain through HoopAI Email, Mailgun, or custom SMTP.
Use MXToolbox Blacklist Check to see if your domain or IP appears on any blacklists. If listed, follow the delisting instructions provided by each blacklist. Google Postmaster Tools also shows domain reputation for Gmail specifically.
HoopAI Email is the built-in email service managed by the HoopAI platform — simpler to set up and billed through your HoopAI account. Mailgun is a third-party service that gives you more control over email infrastructure but requires a separate account and billing. Most users should start with HoopAI Email.
The address may be correct but the receiving server could still reject your email due to: poor sender reputation, failed authentication (SPF/DKIM), content flagged as spam, or the receiving server being temporarily unavailable (soft bounce). Check your authentication setup first.
Yes. Warmup is tied to the sending infrastructure (IP and domain), not your account. Switching providers means you are sending from a new IP, which requires a fresh warmup.
Most DNS changes propagate within 15 minutes to 2 hours. In rare cases, it can take up to 48 hours. Use tools like DNS Checker to monitor propagation in real time.
Low open rates can indicate emails landing in the Promotions tab (Gmail) or Clutter folder (Outlook) rather than the primary inbox. They can also result from poor subject lines, unrecognized sender names, or sending to an unengaged segment. Segment more aggressively and sunset inactive contacts.
Last modified on May 19, 2026