Openrouter uses Customer.io for marketing email and SendGrid for transactional/notifications. They rank #9,444 in the Tranco list of most-popular domains. Their email authentication setup is good (score 80/100).
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.
DMARC reports sent to cloudflare.net. Policy
p=quarantine means receivers actively block or quarantine spoofed mail.
SPF alignment: all 6 observed emails use a return-path aligned with openrouter.ai (cio121019.openrouter.ai, clkmail.openrouter.ai). SPF authenticates the visible From — supports DMARC directly.
DKIM alignment: all 6 observed emails sign with a domain aligned with openrouter.ai (cio121019.openrouter.ai, openrouter.ai). DKIM authenticates the visible From — supports DMARC directly.
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: openrouter.ai, clkmail.openrouter.ai, cio121019.openrouter.ai
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 | 8 | 100.0% |
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 % |
|---|---|---|---|---|---|
| Customer.io | 4 | 100.0% | 0.0% | 0.0% | |
| SendGrid | 2 | 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 openrouter.ai has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Reputation |
|---|---|---|---|
| 143.55.233.8 | v58.v596efc78.use4.send.mailgun.net |
5 | Check → |
| 159.183.147.115 | o5.ptr1737.clerk.dev |
2 | Check → |
| 159.112.253.125 | v5125.v59719d68.use4.send.mailgun.net |
1 | Check → |
Per-IP inbox / promotions / spam is being collected and will appear here as new emails are observed.
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
openrouter.ai | Customer.io 6 SendGrid 2 |
