Back to Blog

Gmail's 2024 Sender Requirements: How to Avoid the Spam Folder

ViMail Team
•
Gmail's 2024 Sender Requirements: How to Avoid the Spam Folder
Gmail's 2024 Sender Requirements: How to Avoid the Spam Folder

Quick news-style summary: what's changed and why it matters

In 2024 Gmail tightened expectations for bulk and transactional senders: stronger authentication, clear sender alignment, transport encryption, and improved sending practices are required to maintain inbox placement. Google points senders to authentication and reputation signals in its Google Postmaster guidance and bulk sender guidelines (see Google's bulk sender guidelines for details). Industry deliverability teams report rising emphasis on DMARC alignment, BIMI adoption for brand trust, and stricter scrutiny on sudden volume spikes.

Source: Google Postmaster Tools and Gmail bulk sender guidelines - see Google’s documentation for setup and troubleshooting.

1. Audit checklist - three quick scans to find issues now

Before you change anything, run this fast audit. Each step gives an exact command or dashboard action so you can get results in minutes.

  1. DNS records and public configuration
    1. Check SPF TXT record: 
      dig +short TXT example.com
      Look for an SPF string like: 
      v=spf1 include:_spf.google.com include:mail.yourprovider.com ~all
    2. Check DKIM selector presence: 
      dig +short TXT selector._domainkey.example.com
      You should see a "v=DKIM1; k=rsa; p=..." public key.
    3. Check DMARC record: 
      dig +short TXT _dmarc.example.com
      Expect something like: 
      v=DMARC1; p=quarantine; rua=mailto:dmarc@example.com; pct=100
  2. IP and domain reputation
    1. Note sending IPs (your MTA and any provider IPs). Use: 
      nslookup -type=mx example.com
      then check IPs against public blacklists and your Google Postmaster dashboard.
    2. In Google Postmaster Tools, verify domain ownership and check the Reputation and Spam Rate graphs for recent spikes (see postmaster.google.com).
  3. Sending domains and header alignment
    1. Ensure the From: domain matches DKIM d= and the Return-Path (envelope-from) domain for alignment.
    2. Sample header to inspect in a received message: 
      From: "Example" <news@example.com>
Return-Path: <bounces@mail.example.com>
Authentication-Results: mx.google.com; dkim=pass header.d=example.com; spf=pass smtp.mailfrom=mail.example.com
      Check for 'dkim=pass' and 'spf=pass' with domains aligned.

Practical takeaway: Fix broken DNS entries first - they're the most common root cause of Gmail placement issues.

2. Technical setup - exact configs for SPF, DKIM, DMARC, BIMI and TLS

Configure these controls precisely. Below are recommended records, commands and MTA settings that Gmail and industry best-practices expect.

SPF (Sender Policy Framework)

  1. Use a concise SPF record that lists all authorized sending hosts. Example: 
    example.com. TXT "v=spf1 ip4:203.0.113.25 include:spf.sendprovider.net -all"
    Use "-all" (hard fail) only after testing; "~all" (soft fail) is safer during rollout.
  2. Check SPF with: 
    dig +short TXT example.com
spfquery --ip 203.0.113.25 --from info@example.com --helo mail.example.com
    (replace with your SPF test tool).

DKIM (DomainKeys Identified Mail)

  1. Generate a key pair (OpenDKIM example): 
    opendkim-genkey -s mail -d example.com
# produces mail.private and mail.txt
  2. Publish the mail.txt value as TXT at mail._domainkey.example.com. Example DNS: 
    mail._domainkey.example.com. TXT "v=DKIM1; k=rsa; p=MIIBIjANBgkq..."
  3. Ensure DKIM signs the header.d (domain) that matches your From: address for 'identifier alignment' (required for DMARC).

DMARC (Domain-based Message Authentication, Reporting & Conformance)

  1. Start in monitor mode: 
    _dmarc.example.com. TXT "v=DMARC1; p=none; rua=mailto:dmarc-agg@example.com; ruf=mailto:dmarc-forensic@example.com; pct=100"
  2. After resolving failures, move to enforcement: 
    v=DMARC1; p=quarantine; pct=100; rua=mailto:dmarc-agg@example.com
    Then to p=reject when confident.
  3. Use DMARC aggregate reports to spot misaligned third-party senders before enforcing reject.

BIMI (Brand Indicators for Message Identification)

  1. Publish a BIMI record (requires a verified DMARC policy of quarantine or reject and a hosted SVG): 
    default._bimi.example.com. TXT "v=BIMI1; l=https://assets.example.com/logo.svg; a=https://bimi-verifier.example.net/cert.pem"
  2. BIMI improves brand recognition in supporting inboxes (Gmail supports BIMI for some domains) and can improve user engagement and trust.

TLS, MTA-STS and TLS Reporting

  1. Support TLS 1.2+ and strong ciphers on your SMTP servers. For Postfix, example config lines: 
    smtpd_tls_protocols = !SSLv2,!SSLv3,!TLSv1
smtpd_tls_mandatory_protocols = !SSLv2,!SSLv3,!TLSv1
  2. Enable MTA-STS: publish policy at mta-sts.example.com/.well-known/mta-sts.txt and a TXT policy at _mta-sts.example.com.
  3. Optionally enable TLS reporting (TLSRPT) to receive telemetry on delivery encryption issues.

Practical takeaway: Authentication + encryption are table stakes. If Gmail can't validate SPF/DKIM/DMARC and TLS, deliverability declines rapidly.

3. Sending best practices - how to send so Gmail honors your messages

Authentication gets you in the game; sending practices determine whether you stay in the inbox. Follow these numbered steps.

  1. List hygiene and consent
    1. Remove hard bounces immediately. Hard-bounce rate target: as close to 0% as possible; many ESPs enforce removal above thresholds.
    2. Suppress inactive users: create an inactivity workflow (e.g., 90+ days) to re-engage or remove addresses.
  2. Segmentation and content relevance
    1. Segment by recency and engagement; send higher volume to your most-engaged cohorts.
    2. Use clear From name and consistent sending domain. Avoid deceptive subject lines.
  3. Control volume and ramp-up
    1. When introducing new IPs or domains, warm them up slowly: start at low volume (hundreds/day) and double volume every 24-72 hours while monitoring bounce and complaint metrics.
    2. Avoid sudden spikes. Gmail's systems flag abrupt changes in sending patterns as risk signals.
  4. Authenticate third-party senders
    1. If using an ESP or third-party system, ensure they can sign DKIM with your domain (delegated selector) and are included in your SPF record or use a subdomain for third-party sends.
    2. Example: use news.example.com with its own DKIM key and SPF record, then align From: to that subdomain.
  5. Respect complaint rates and feedback loops
    1. Monitor feedback loops if available and act on complaints within 48 hours - remove complainers.
    2. Maintain complaint rates under industry thresholds (many inbox providers consider >0.3% problematic).

Practical takeaway: Authenticate and segment so your best recipients get the most mail. Warm up IPs and minimize complaints.

4. Monitoring and troubleshooting - use Google Postmaster, DMARC reports and reputation metrics

Continuous monitoring is critical. These tools and reports give you the signals Gmail uses.

  1. Google Postmaster Tools (GPT)
    1. Verify your domain at postmaster.google.com. Once verified, check:
      • IP and domain reputation
      • Spam rate
      • Authentication (SPF/DKIM) status
      • Encryption (TLS) status
    2. Look for upward trends in spam rate or drops in reputation after any configuration change - that gives you a rollback point.
  2. DMARC aggregate reports
    1. Collect and parse aggregate reports (RUA). Use a parser or service to visualize SPF/DKIM alignment failures and identify rogue senders.
    2. Action: fix misconfigured partners or move them onto subdomains to avoid harming the main domain's reputation.
  3. Logs and forensic analysis
    1. Collect SMTP logs and message samples for failed deliveries. Look for specific Gmail rejection codes or '550' series errors.
    2. Inspect message headers from recipients who reported spam to see authentication failures and content-related clues.
  4. Reputation and deliverability scorecards
    1. Track complaint rates, bounce rates, engagement rates and inbox placement tests (use seed lists). Compare before/after changes.

Practical troubleshooting steps:

  1. If Gmail flags spam rate high: reduce volume, pause campaigns to unengaged lists, and resolve authentication failures.
  2. If DKIM fails intermittently: rotate keys and ensure DKIM selectors published match your MTA signing config (match selector name in DNS to domain in headers).
  3. If IP reputation is low: move sending to warmed IPs and limit sends from bad IPs until reputation improves.

5. Real-world case study - a quick win for a mid-sized ecommerce sender

This is an anonymized composite of common scenarios that deliver practical steps and metrics.

Problem

A mid-sized ecommerce company saw declining Gmail inbox placement over three months. Symptoms: rising spam complaints, DKIM failures for one campaign, and sudden volume spikes after a sale.

Actions taken (step-by-step)

  1. Run DNS audit and found DKIM selector mismatch for transactional system. Resolved by publishing correct selector._domainkey TXT and restarting the signing service.
  2. Updated SPF to include their ESP then changed to use a dedicated sending subdomain (transactions.example.com) to isolate reputation.
  3. Entered DMARC in monitor mode and parsed RUA reports; identified two third-party tools sending unauthenticated mail - they were moved to subdomains.
  4. Implemented 7-day IP warm-up for a new sending cluster; ramped volume slowly and monitored Postmaster Tools.
  5. Removed addresses inactive for 180+ days and created a re-engagement flow rather than sending mass reactivations.

Outcome

Within two weeks the sender saw measurable improvements in Google Postmaster: domain reputation recovered and spam-rate graph declined. The sender reported a rise in Gmail inbox placement for targeted campaigns from the low 60s to the mid-90s percentile of seed-list placements after fixes and warm-up (results vary by sender).

Key lesson: Fix authentication first, isolate third-party sends, then address list hygiene and volume control.

6. Printable checklist - quick actions to avoid Gmail's spam folder

Print or copy this list for operational use.

  1. DNS & Authentication
    • [ ] SPF present and includes all senders
    • [ ] DKIM selector published and signing correctly
    • [ ] DMARC published (start with p=none) and RUA configured
    • [ ] BIMI prepared if brand logo expected
  2. Encryption & Transport
    • [ ] TLS 1.2+ enforced on SMTP
    • [ ] MTA-STS and TLSRPT configured
  3. Sending Practices
    • [ ] Warm-up plan for new IPs/domains
    • [ ] Remove hard bounces and suppress complainers
    • [ ] Segment by engagement and limit daily volume per cohort
  4. Monitoring
    • [ ] Verify domain in Google Postmaster Tools
    • [ ] Collect DMARC RUA and analyze weekly
    • [ ] Track complaint and bounce rates daily
  5. Troubleshooting
    • [ ] Collect headers from messages marked as spam
    • [ ] Map third-party senders and move to subdomains if unfixable

Conclusion - recap and next practical steps

Gmail's 2024 requirements make authentication, encryption, and disciplined sending the non-negotiable base for inbox placement. Start with the audit (DNS, IPs, alignment), fix SPF/DKIM/DMARC, enable TLS/MTA-STS, and enforce good list and volume practices. Use Google Postmaster Tools and DMARC reports to monitor the exact signals Gmail uses. Small, methodical fixes (authentication alignment, warmed IPs, and cleaned lists) typically produce the fastest inbox improvements.

Quick checklist: Audit DNS → Fix SPF/DKIM → Enable DMARC monitor → Warm IPs → Clean lists → Monitor Postmaster & DMARC.

Next step: Run the DNS and header checks in this guide now, publish any missing records, and monitor Google Postmaster for early feedback.

Ready to Create Your First Video?

Join thousands of professionals using ViMail to create engaging video messages.

Get Started Free