Partnerstack uses HubSpot for marketing email and SendGrid for transactional/notifications. They rank #36,994 in the Tranco list of most-popular domains. Email goes out from 2 different subdomains. Their email authentication setup is solid (score 85/100). We've recorded 4 ESP changes since first observing this brand.
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 vali.email. Policy
p=reject means receivers actively block or quarantine spoofed mail.
SPF alignment: 80% of observed emails use an aligned return-path (em1926.partnerstackmail.com); the rest use third-party paths (bf08x.hubspotemail.net) where DMARC has to rely on DKIM alignment.
DKIM alignment: all 70 observed emails sign with a domain aligned with partnerstack.com (partnerstackmail.com, partnerstack.com). DKIM authenticates the visible From — supports DMARC directly.
TLS: modern — 85% TLS 1.3 (across 33 sends).
Delivery: fast — 89% of emails in the last 7 days arrive in under 10 seconds (across 9 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).
Zendesk 6ESPs 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: partnerstack.com, em1926.partnerstackmail.com, bf08x.hubspotemail.net, partnerstackmail.com
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 | 84 | 98.8% |
| promotions | 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 % |
|---|---|---|---|---|---|
| HubSpot | 15 | 100.0% | 0.0% | 0.0% | |
| Zendesk | 6 | 100.0% | 0.0% | 0.0% | |
| SendGrid | 53 | 98.1% | 1.9% | 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 partnerstack.com has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Placement | Reputation |
|---|---|---|---|---|
| 143.244.88.192 | bd77f32.bf08x.hubspotemail.net |
7 | — | Check → |
| 143.244.88.193 | bd77f33.bf08x.hubspotemail.net |
3 | 1 | Check → |
| 143.244.88.133 | bd77f2f.bf08x.hubspotemail.net |
2 | — | Check → |
| 108.179.150.171 | 4f2o09.bf08x.hubspotemail.net |
2 | — | Check → |
| 192.161.149.3 | mta-out3.pod19.use1.zdsys.com |
2 | — | Check → |
| 192.161.149.12 | mta-out12.pod19.use1.zdsys.com |
2 | — | Check → |
| 192.161.149.6 | mta-out6.pod19.use1.zdsys.com |
1 | — | Check → |
| 143.244.88.159 | bd77f25.bf08x.hubspotemail.net |
1 | — | Check → |
| 192.161.149.4 | mta-out4.pod19.use1.zdsys.com |
1 | — | Check → |
| 143.244.88.188 | bd77f3y.bf08x.hubspotemail.net |
1 | 1 | Check → |
| 143.244.88.178 | bd77f3o.bf08x.hubspotemail.net |
1 | 1 | Check → |