Hunter uses Customer.io for marketing email and Postmark for transactional/notifications. They rank #30,804 in the Tranco list of most-popular domains. Email goes out from 2 different subdomains. Their email authentication setup is solid (score 100/100).
Non-ESP tools detected in this brand's emails. Independent of who sends — a brand can use any combination.
| HTML builder |
Authentication signals observed in this brand's emails. SPF, DKIM and DMARC are the standard sender-authentication stack — see the DMARC policy below for whether spoofing is actually blocked or just monitored. One-click unsubscribe meets Google & Yahoo's bulk-sender requirements.
SPF / DKIM / DMARC above reflect the last 9 emails we've observed. DMARC policy is read live from DNS.
DMARC reports sent to Postmark DMARC. Policy
p=reject means receivers actively block or quarantine spoofed mail.
SPF alignment: all 26 observed emails use a return-path aligned with hunter.io (cio49840.mail.hunter.io, cio49840.hunter.io, pmbounces.hunter.io). SPF authenticates the visible From — supports DMARC directly.
DKIM alignment: all 26 observed emails sign with a domain aligned with hunter.io (cio49840.mail.hunter.io, cio49840.hunter.io, hunter.io). DKIM authenticates the visible From — supports DMARC directly.
TLS: 19% TLS 1.3, 81% TLS 1.2 (across 16 sends).
Delivery: fast — 100% of emails in the last 7 days arrive in under 10 seconds (across 4 sends).
Gmail's own filter showed these warnings to real subscribers in their inbox — independent of SPF/DKIM/DMARC pass/fail status. A consistent pattern often signals reputation issues or brand-impersonation concerns.
Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).
None — only the primary ESP(s) shown aboveESPs we've seen sending email for this brand. Green = confirmed by SPF, sender IP rDNS, or known infra pairing (label shows the source). Grey = observed but not yet confirmed by SPF or PTR.
ESPs this brand has authorized in their SPF record. We confirm them with a green ✓ only after seeing recurring use (3+ emails across 2+ days). Until then they stay here — either we haven't observed any email yet, or we've seen a handful but not enough to call them a regular sender for the brand.
Probed: hunter.io, cio49840.mail.hunter.io, cio49840.hunter.io, pmbounces.hunter.io, mail.hunter.io
Folder distribution across all emails from this brand observed in Gmail inboxes. High inbox % = good deliverability; spam appearances are the headline signal.
| Folder | Count | Share |
|---|---|---|
| inbox | 23 | 95.8% |
| spam | 1 | 4.2% |
Which ESP's emails are landing where. Sorted by spam % so problem senders surface first. Brands using one ESP for marketing and another for transactional often see very different placement profiles per ESP. Per-ESP folder data only started being captured recently — counts here may be smaller than the total above until backfill catches up.
| ESP | Emails | Placement | Inbox % | Tabs % | Spam % |
|---|---|---|---|---|---|
| Postmark | 3 | 66.7% | 0.0% | 33.3% | |
| Customer.io | 21 | 100.0% | 0.0% | 0.0% |
Daily observations per ESP. Brands often run multiple ESPs concurrently — marketing on one, transactional on another — so this chart shows usage rather than switches.
IP addresses hunter.io has been observed sending from, and where their mail landed in Gmail.
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
mail.hunter.io | Customer.io 20 | |
hunter.io | Customer.io 4 Postmark 3 |