This tutorial explains how to set up SPF, DKIM and DMARC for SMTP VPS email authentication. These DNS records help receiving mail servers verify whether email from your domain is legitimate.
CybroHost SMTP VPS Hosting includes Port 25 and 465 open, PTR support, full root access and NVMe storage for users who need advanced email server control.
Step 1: Understand SPF
SPF tells receiving servers which IP addresses are allowed to send email for your domain. A basic SPF record may look like this:
v=spf1 ip4:YOUR_SERVER_IP -all
Replace YOUR_SERVER_IP with your SMTP VPS IP address.
Step 2: Understand DKIM
DKIM adds a digital signature to your outgoing email. Your mail server generates a DKIM key, and you publish the public key as a DNS TXT record.
Step 3: Understand DMARC
DMARC tells receiving servers what to do when messages fail SPF or DKIM. A starter DMARC record may look like this:
v=DMARC1; p=none; rua=mailto:reports@yourdomain.com
Start with p=none for monitoring. Later, you can move to quarantine or reject after testing.
Step 4: Add Records in DNS
Log in to your DNS provider and add SPF, DKIM and DMARC as TXT records. Save the changes and wait for propagation.
Step 5: Test Your Records
Use an email authentication checker to verify your DNS records. Cloudflare explains these records here: SPF, DKIM and DMARC explained.
Step 6: Check PTR Record
For SMTP VPS, PTR or reverse DNS should also be configured. CybroHost SMTP VPS includes PTR support, which is important for email trust.
Final Recommendation
Set up SPF, DKIM, DMARC and PTR before sending serious email from your SMTP VPS. Good authentication helps protect your domain and improves trust with receiving mail servers.
FAQs
Do I need SPF, DKIM and DMARC?
Yes, these records are important for email authentication and domain protection.
What DMARC policy should I start with?
Start with p=none while testing, then move to stricter policies later.
Does SMTP VPS need PTR?
Yes, PTR is strongly recommended for mail server reputation.