BillionMail emails going to spam even though SPF, DKIM and DMARC pass
Three green checks and still the spam folder. It's one of the most common complaints with any self-hosted mail server. The reason: SPF, DKIM and DMARC only prove the email is really from you. They don't prove you're worth reading. Gmail and Outlook decide that from your server setup, your reputation and how people react to your mail.
Go through this list top to bottom. The first items are quick technical fixes; the later ones take time.
1. Reverse DNS (PTR)
Your server's IP should point back to your mail host name. Without it, many receivers treat you as a home computer or a bot. On our first test this was the only real error. The tester said: "The sending server's IP address doesn't have a matching reverse DNS record."
![[Image: attachment.php?aid=427]](https://adminsforum.com/attachment.php?aid=427)
The answer must be your mail host (e.g. ), and that name's A record must point back to the same IP. Only your VPS provider can set PTR: open a ticket or look for "Reverse DNS" in their panel.
2. HELO name
If your server introduces itself as or a container name, spam filters notice. See BillionMail SSL and hostname fix, Part 2.
3. Blacklists
Cheap VPS IPs are often recycled from earlier spammers. Check your IP and domain on a blacklist checker, or run a test with a free email tester (our deliverability guide shows how). If you're listed, follow that list's delisting steps, or ask your provider for a clean IP.
4. Content
5. One-click unsubscribe
Gmail and Yahoo require bulk senders to offer one-click unsubscribe. Keep Unsubscribe link switched on in every task. If unsubscribing is hard, people press "Report spam" instead, which is far worse for you.
6. List quality
Only mail people who asked for it. Bought or scraped lists contain dead addresses and spam traps, and one campaign to such a list can ruin a new IP. Remove addresses that bounce, and stop mailing people who haven't opened anything in months.
7. Warm up your IP and domain
A brand-new server that suddenly sends 10,000 emails looks exactly like a spammer. Keep the IP Warmup switch on in your tasks and grow slowly over two to four weeks: start with a few hundred of your most engaged readers, then roughly double every few days if results stay good. Need volume right away? Use an SMTP relay under SMTP while your own IP builds a reputation.
8. Watch Gmail's spam rate
Sign up for Google Postmaster Tools (free) and add your sending domain. It shows how often Gmail users mark your mail as spam. Google's sender rules ask bulk senders to keep this under 0.3%, and ideally under 0.1%. Microsoft offers a similar service called SNDS for your IP.
9. Engagement
Replies, opens, moving mail from spam to the inbox and adding you to contacts all teach Gmail that people want your email. Ask a question readers can answer, and send from an address that accepts replies.
How long until it improves?
Technical fixes (PTR, HELO, DNS) work within a day. Reputation takes weeks of steady, wanted mail. If you fixed the setup and still land in spam, the answer is usually time and smaller, more engaged sends, not more settings.
Sources: Google: email sender guidelines · Gmail: Postmaster Tools · RFC 8058: one-click unsubscribe
More BillionMail troubleshooting
Applies to BillionMail 4.9 installed through aaPanel or the install script, October 2026.
Three green checks and still the spam folder. It's one of the most common complaints with any self-hosted mail server. The reason: SPF, DKIM and DMARC only prove the email is really from you. They don't prove you're worth reading. Gmail and Outlook decide that from your server setup, your reputation and how people react to your mail.
Go through this list top to bottom. The first items are quick technical fixes; the later ones take time.
1. Reverse DNS (PTR)
Your server's IP should point back to your mail host name. Without it, many receivers treat you as a home computer or a bot. On our first test this was the only real error. The tester said: "The sending server's IP address doesn't have a matching reverse DNS record."
Code:
dig +short -x YOUR_SERVER_IPCode:
bm.example.com.2. HELO name
If your server introduces itself as
Code:
localhost3. Blacklists
Cheap VPS IPs are often recycled from earlier spammers. Check your IP and domain on a blacklist checker, or run a test with a free email tester (our deliverability guide shows how). If you're listed, follow that list's delisting steps, or ask your provider for a clean IP.
4. Content
- Write like a person. Our first test email used "free", "marketing platform" and "campaign" in a short text, and the tester flagged the wording.
- Don't send one big image with no text. Keep a healthy text-to-image balance.
- Avoid URL shorteners, and link to your own domain where possible.
- Keep the From name and address the same every time.
- Explain why the person gets the email ("You get this because you joined our newsletter").
5. One-click unsubscribe
Gmail and Yahoo require bulk senders to offer one-click unsubscribe. Keep Unsubscribe link switched on in every task. If unsubscribing is hard, people press "Report spam" instead, which is far worse for you.
6. List quality
Only mail people who asked for it. Bought or scraped lists contain dead addresses and spam traps, and one campaign to such a list can ruin a new IP. Remove addresses that bounce, and stop mailing people who haven't opened anything in months.
7. Warm up your IP and domain
A brand-new server that suddenly sends 10,000 emails looks exactly like a spammer. Keep the IP Warmup switch on in your tasks and grow slowly over two to four weeks: start with a few hundred of your most engaged readers, then roughly double every few days if results stay good. Need volume right away? Use an SMTP relay under SMTP while your own IP builds a reputation.
8. Watch Gmail's spam rate
Sign up for Google Postmaster Tools (free) and add your sending domain. It shows how often Gmail users mark your mail as spam. Google's sender rules ask bulk senders to keep this under 0.3%, and ideally under 0.1%. Microsoft offers a similar service called SNDS for your IP.
9. Engagement
Replies, opens, moving mail from spam to the inbox and adding you to contacts all teach Gmail that people want your email. Ask a question readers can answer, and send from an address that accepts replies.
How long until it improves?
Technical fixes (PTR, HELO, DNS) work within a day. Reputation takes weeks of steady, wanted mail. If you fixed the setup and still land in spam, the answer is usually time and smaller, more engaged sends, not more settings.
Sources: Google: email sender guidelines · Gmail: Postmaster Tools · RFC 8058: one-click unsubscribe
More BillionMail troubleshooting
- Port 25 blocked: emails not sending
- SSL certificate won't apply
- DKIM fails although the record exists
- Emails stuck in the send queue
- Can't open the dashboard
- Webmail (Roundcube) problems
- Update safely and roll back
Applies to BillionMail 4.9 installed through aaPanel or the install script, October 2026.