Why is my email going to spam?
Improve email deliverability by configuring SPF, DKIM, DMARC, reverse DNS, and monitoring your sending reputation. A practical diagnosis guide.
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When legitimate email ends up in spam, the cause is almost always one of these: missing authentication records (SPF, DKIM, DMARC), a blacklisted sending IP, a poor sender reputation, or email content that triggers spam filters. Work through this guide from top to bottom to diagnose and fix each layer.
SPF record
SPF declares which servers may send email on behalf of your domain. Receiving mail servers check SPF before accepting or rejecting messages.
Check your SPF
Run a DNS lookup for your domain's TXT records and look for a record starting with v=spf1:
nslookup -type=TXT yourdomain.com
Or use a DNS lookup tool like nslookup or dig, which can test SPF, DKIM, and DMARC. See DNS resolution issues for command examples.
Fix your SPF
In cPanel, go to Email → Email Deliverability and click Repair. This automatically creates a correct SPF record for your domain. A typical SPF record looks like:
v=spf1 a mx ip4:YOUR.SERVER.IP ~allA domain can only have one SPF record. Multiple TXT records starting with v=spf1 cause SPF to fail. If you need to authorize multiple senders, combine them into a single record: v=spf1 include:mailprovider.com a mx ~all.
DKIM signature
DKIM adds a cryptographic signature to outgoing emails so recipients can verify the message wasn't altered in transit and genuinely came from your domain.
Enable DKIM in cPanel
Go to cPanel → Email → Email Deliverability. If DKIM shows "Not installed" or "Invalid", click Repair. cPanel will generate the key pair, publish the public key as a DNS TXT record, and configure Exim to sign outgoing mail automatically.
After enabling DKIM, the DNS record must propagate before receiving servers can verify signatures. This takes up to 1–4 hours. Use the Email Check tool to confirm DKIM is visible after propagation.
DMARC policy
DMARC tells receiving servers what to do when an email fails SPF or DKIM: monitor, quarantine (send to spam), or reject it outright.
Add a DMARC record
Add a TXT record in your DNS zone with the name _dmarc:
# Start in monitor mode-you'll get reports but no emails are blocked
v=DMARC1; p=none; rua=mailto:postmaster@yourdomain.com
# After reviewing reports, move to quarantine or reject
v=DMARC1; p=quarantine; rua=mailto:postmaster@yourdomain.comReverse DNS (PTR record)
A PTR record maps your server's IP address back to a hostname. Many receiving mail servers check that this reverse lookup exists and matches the server's hostname. Without it, your emails are more likely to be flagged.
For VPS and dedicated servers, you can request a custom PTR record via CustomerPanel → Support. For shared hosting, the server's PTR is managed by UnderHost and is typically already configured correctly.
Blacklist check
If your server IP is on a major email blacklist (RBL), receiving servers will reject or spam-score your messages before even looking at SPF or DKIM.
See Email blacklists-check and delist your IP to check your status and find which blacklists have listed you with removal instructions.
Blacklists flag IPs for sending spam. Before requesting delisting, identify and stop the source: a compromised WordPress site, an infected script, or a weak email password being used by spammers. If you don't fix the root cause, the IP will be relisted quickly.
Email content
Even with perfect authentication, poorly written emails can trigger spam filters. Common content-level issues:
- Excessive use of ALL CAPS or "!!!" in subject lines
- Spam trigger words like "Free", "Winner", "Click here", "Make money"
- Very short text with heavy image usage (no alt text)
- Missing or misleading physical address (required by CAN-SPAM and GDPR for marketing emails)
- Broken HTML or encoding issues
- Missing unsubscribe link in bulk/marketing email
Full deliverability checklist
| Check | Where to fix | Status |
|---|---|---|
| SPF record exists and is valid | cPanel → Email Deliverability | |
| DKIM is enabled and signing | cPanel → Email Deliverability | |
| DMARC record published | DNS Zone Editor | |
| PTR (reverse DNS) record set | Open support ticket | |
| IP not on major blacklists | RBL Check tool | |
| No duplicate SPF records | DNS Zone Editor | |
| Email content is clean | Review before sending |
Related: Email not sending-troubleshooting outgoing email | Email blacklists-check and delist your IP or domain | How to set up reverse DNS (PTR records) for your server IP | How to set up email accounts in cPanel
Need email hosting?
UnderHost shared and managed hosting include mailbox, webmail, DNS, SPF/DKIM, and email support for your domain.
