What to check from the dashboard
Spam-folder placement isn't a single failure — it's a signal that something measurable is off about your sender setup or your audience engagement. AcelleMail's dashboard exposes the three signals receivers use to make the spam vs. inbox decision.
Open a recently sent campaign and click Insights (or Subscribers → Engagement tab):
What you're reading:
- Open rate < 5% for a list you regularly engage → recipients aren't seeing it in their inbox at all. Spam placement likely.
- Open rate normal but click-through 0 → message rendering broken (suspicious content) or recipients are opening, scanning, and not engaging. Reputation drift.
- High open rate but high unsubscribe + complaint rate → content mismatched to subscriber expectations. ISPs penalize this.
Open the sending server configuration
Most spam-folder cases trace back to the sending side. Settings → Sending servers → click your active server:
Three things to verify here:
- Authentication status — SPF / DKIM / DMARC verification chips should all be green. Red means the receiving servers can't confirm you're authorized to send for the domain.
- Daily quota — if you're hitting the quota every send, sends spill over into the next day's batch. Some ISPs interpret this as bulk-spam pattern.
- Bounce + complaint rate (last 24h) — if either is >5%, ISPs throttle your IP. Sustained high rates push you into spam folders.
Run the test diagnostic
Inside the sending server detail, Test button sends a one-off message you can inspect:
Send to your own address. Open the email in Gmail / Outlook / Apple Mail.
- Email arrived in Inbox? → sending setup is OK. The spam problem is content / recipient-side (engagement, subject lines, frequency).
- Email arrived in Spam? → sending setup is the issue. Move to operator section.
- Email didn't arrive at all → outright blocked. IP is on a blocklist. Operator section.
In Gmail, click the email → three-dot menu → Show original. The headers reveal:
Authentication-Results: ... spf=pass dkim=pass dmarc=pass(all three should pass)Received-SPFandDKIM-Signaturepresence
If any of the three says fail or is missing, that's your fix target.
Common UI causes and the fix from the dashboard
| What you see | Likely cause | What to do |
|---|---|---|
| Sending server: red SPF / DKIM / DMARC chip | DNS records missing or incorrect | Click Verify → AcelleMail walks you through the DNS records to add. Re-verify after publishing. |
| Insights: open rate dropped 40% in last 3 sends | IP reputation degrading | Pause campaigns. Run Subscribers → Email verification on the list. Investigate recent content for unsubscribe spikes. |
| Test diagnostic lands in spam, headers show "spf=fail" | SPF record doesn't include your sending IP / provider | Update SPF record at your DNS host. Add the sending vendor's SPF include (e.g. include:amazonses.com). |
| Test diagnostic lands in spam, body has spam-trigger words | Content filtering | Re-review subject line + first paragraph. Avoid ALL CAPS, excessive punctuation, link-only content. |
| Test diagnostic doesn't arrive at all | IP blocklisted | Check the sending IP at mxtoolbox.com → blocklist lookup. Request delisting per the blocklist's process. |
Pause and isolate the bad cohort
If only some recipients land in spam, segment the list:
- Subscribers → Filter by domain → check open rates per ISP (Gmail / Outlook / Yahoo / corporate).
- A 0% open rate on @gmail.com while @outlook.com is normal → your Gmail-side reputation is hurt. Investigate recent send patterns to Gmail addresses.
- Pause sends to the problem segment until you've remediated content / reputation.
Advanced: SPF / DKIM / DMARC tuning for operators
The three authentication standards form the deliverability foundation. All three must pass for ISPs to trust the sender.
SPF (Sender Policy Framework — RFC 7208)
A DNS TXT record listing which IPs / domains are authorized to send for your domain. Lookup:
dig TXT yourdomain.com +short | grep spf
# Expected: "v=spf1 include:amazonses.com -all"
Common gotchas:
- Multiple
v=spf1records on the same domain — SPF requires exactly ONE. Merge into one record. ~all(soft fail) instead of-all(hard fail) —-allis preferred for production.- Sending IP not in the record. Use
digto verify; add the include statement.
DKIM (DomainKeys Identified Mail — RFC 6376)
Cryptographic signature on every outgoing message. The public key is published in DNS at <selector>._domainkey.yourdomain.com. AcelleMail generates the keypair via the sending-server's Verify domain wizard.
# Check the DKIM record exists
dig TXT default._domainkey.yourdomain.com +short
# Expected: "v=DKIM1; k=rsa; p=MIGfMA0..."
Common gotchas:
- DNS record published but with line breaks — receivers can't parse. Re-publish as single-line.
- Selector mismatch — AcelleMail uses
<servername>._domainkeyby default; if you customized the selector during install, verify the record name matches.
DMARC (Domain-based Message Authentication, Reporting & Conformance — RFC 7489)
Tells receivers what to do when SPF or DKIM fails:
dig TXT _dmarc.yourdomain.com +short
# Expected: "v=DMARC1; p=quarantine; rua=mailto:[email protected]"
Migration path (always start permissive, ramp to strict):
p=none; rua=mailto:[email protected]— monitor; receivers send aggregate reports, no policy applied.- After 2-4 weeks of clean reports →
p=quarantine; pct=10— 10% of failing mail goes to spam. - Ramp
pctto 100 over 2 weeks → switch top=rejectonly after 100% pass rate.
Going straight to p=reject without ramping breaks ALL your mail if any auth is misconfigured.
Inspecting Authentication-Results of a received message:
# Send a test → grep the headers
grep -E "Authentication-Results|Received-SPF|DKIM-Signature" /path/to/saved-email
Look for dmarc=pass AND spf=pass AND dkim=pass. Any failure → fix that side specifically before retrying.
Engagement-driven reputation — ISPs increasingly weight subscriber engagement over pure auth. Even with green SPF/DKIM/DMARC, if your open rate is <10% over a 30-day window, Gmail / Outlook may demote you. Mitigation: aggressive list hygiene (unsubscribe inactive subscribers after 6 months), re-engagement campaigns to dormant cohorts before re-engaging them in regular sends.
Blocklist monitoring — periodic check at mxtoolbox.com for your sending IP + sending domain. Major lists: Spamhaus SBL/XBL/CSS, SpamCop, Barracuda. Each list has its own delisting form.
Related articles
- Decoding bounce messages
- How to set up SPF, DKIM, and DMARC records
- Email list hygiene — clean your list for better deliverability
- SPF record deep dive
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