When running mail server diagnostics through tools like dkimvalidator.com, the SPF_HELO_NONE warning appears when your Postfix server's HELO/EHLO identification lacks SPF records. While this doesn't directly impact your spam score, it creates a vulnerability where attackers could spoof your HELO identity during SMTP conversations.

Many administrators only configure SPF for their @domain records, forgetting that:

• SMTP servers identify themselves during the HELO/EHLO phase
• Receiving servers may perform separate SPF checks on the HELO identity
• Absence creates an open relay detection risk

Create a dedicated DNS TXT record for your mail server's hostname:

; DNS zone file entry
mail.yourdomain.com. IN TXT "v=spf1 a mx ~all"

For Postfix configuration, ensure your main.cf contains:

smtpd_helo_restrictions = 
    permit_mynetworks
    reject_invalid_helo_hostname
    reject_non_fqdn_helo_hostname
    check_helo_access hash:/etc/postfix/helo_access
    permit

Create the helo_access file:

# /etc/postfix/helo_access
mail.yourdomain.com OK

For servers with dynamic IPs or cloud hosting:

; SPF record allowing AWS SES and your elastic IP
mail.yourdomain.com. IN TXT "v=spf1 include:amazonses.com ip4:203.0.113.45 -all"

Postfix policy server implementation (Python example):

import sys
import spf

def check_helo_spf(helo, ip):
    query = spf.check2(i=ip, s=helo, h=helo)
    return query[0] == 'pass'

if __name__ == '__main__':
    print(check_helo_spf(sys.argv[1], sys.argv[2]))

Test your configuration with:

dig TXT mail.yourdomain.com +short
postconf -n | grep helo
swaks --helo mail.yourdomain.com --server your.mail.server

For automated monitoring, add this to your Nagios/Icinga checks:

#!/bin/bash
SPF_RECORD=$(dig +short TXT mail.$1 | grep -E 'v=spf1')
[[ -z "$SPF_RECORD" ]] && exit 2 || exit 0

• Using CNAME records instead of direct A/MX records for HELO identity
• Forgetting to update SPF when changing cloud providers
• Over-restrictive policies causing false positives (-all instead of ~all)

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When running email configuration tests through tools like dkimvalidator.com, many Postfix administrators encounter this warning:

0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record

This indicates your mail server's HELO/EHLO identification isn't covered by an SPF record. While it doesn't directly impact your spam score, it's considered a configuration gap in email authentication.

Modern email systems perform two SPF checks:

1. MAIL FROM domain check (standard SPF validation)
2. HELO/EHLO hostname check (often overlooked)

Missing HELO SPF makes your server vulnerable to backscatter attacks and may trigger additional scrutiny from some receiving mail servers.

Here's the complete solution:

Step 1: Create HELO SPF Record

Add a TXT record for your mail server's hostname (what appears in HELO/EHLO):

v=spf1 a mx ~all

Example DNS entry if your HELO is mail.example.com:

mail.example.com. IN TXT "v=spf1 a mx ~all"

Step 2: Verify Postfix HELO Configuration

Check your current HELO name:

postconf -n | grep myhostname

Output should match your DNS record:

myhostname = mail.example.com

Step 3: Adjust SPF Policy (Optional)

For stricter validation, modify /etc/postfix-policyd-spf-python/policyd-spf.conf:

HELO_reject = Fail
Mail_From_reject = Fail

Problem: Changes not taking effect
Solution: Clear DNS cache and restart Postfix:

systemctl restart postfix
systemctl restart postfix-policyd-spf

Problem: Multiple HELO names
Solution: For servers with multiple hostnames, create SPF records for each:

server1.example.com. IN TXT "v=spf1 a ~all"
server2.example.com. IN TXT "v=spf1 a ~all"

Use these commands to verify:

dig TXT mail.example.com +short
postfix check
postsuper -d ALL

For comprehensive testing, send test emails through:

swaks --to test@dkimvalidator.com --server mail.example.com