Apollo uses Customer.io for marketing email and SendGrid for transactional/notifications. They rank #7,579 in the Tranco list of most-popular domains. Email goes out from 2 different subdomains. Their email authentication setup is solid (score 85/100). Missing: SPF.
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 10 emails we've observed. DMARC policy is read live from DNS.
DMARC reports sent to apollo.io. Policy
p=reject means receivers actively block or quarantine spoofed mail.
SPF alignment: 94% of observed emails use an aligned return-path (cio54818.mail.apollo.io, cio54818.apollo.io, outbound.intercom.apollo.io); the rest use third-party paths (capitani.marketing, gmail.com) where DMARC has to rely on DKIM alignment.
DKIM alignment: all 59 observed emails sign with a domain aligned with apollo.io (cio54818.mail.apollo.io, cio54818.apollo.io, apollo.io). DKIM authenticates the visible From — supports DMARC directly.
TLS: 10% TLS 1.3, 90% TLS 1.2 (across 21 sends).
Delivery (last 7 days): 13% under 10 seconds, 0% over 1 minute (across 8 sends).
Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).
Intercom 4ESPs 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: apollo.io, cio54818.mail.apollo.io, cio54818.apollo.io, gmail.com, outbound.intercom.apollo.io, capitani.marketing, em3811.apollo.io, mail.apollo.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 | 71 | 82.6% |
| promotions | 14 | 16.3% |
| spam | 1 | 1.2% |
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 % |
|---|---|---|---|---|---|
| Customer.io | 73 | 82.2% | 16.4% | 1.4% | |
| Intercom | 4 | 50.0% | 50.0% | 0.0% | |
| SendGrid | 4 | 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 apollo.io has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Placement | Reputation |
|---|---|---|---|---|
| 159.112.243.135 | v5135.v5be21903.use4.send.mailgun.net |
24 | — | Check → |
| 159.112.241.77 | v577.v5c4dda55.use4.send.mailgun.net |
19 | 2 | Check → |
| 198.244.52.92 | a92.a355d2fe.use4.send.mailgun.net |
10 | — | Check → |
| 192.174.84.112 | mta-174-84-112.intercom.com.sparkpostmail.com |
1 | — | Check → |
| 192.174.84.111 | mta-174-84-111.intercom.com.sparkpostmail.com |
1 | — | Check → |
| 192.174.84.146 | mta-174-84-146.intercom.com.sparkpostmail.com |
1 | — | Check → |
| 192.174.84.145 | mta-174-84-145.intercom.com.sparkpostmail.com |
1 | — | Check → |
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
apollo.io | Customer.io 40 SendGrid 6 Intercom 4 | |
mail.apollo.io | Customer.io 41 |