Sparkloop uses Kit for marketing email and Postmark for transactional/notifications. They rank #39,640 in the Tranco list of most-popular domains. We've also observed sends via 2 other providers: Userlist, Amazon SES. Their email authentication setup is good (score 73/100). Missing: DMARC enforcement. We've recorded 3 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 sparkloop.app. Policy
p=none is monitor-only — receivers won't act on spoofing yet.
SPF alignment: 68% of observed emails use an aligned return-path (ckespa.sparkloop.app, pm-bounces.sparkloop.app, bounce.sparkloop.app); the rest use third-party paths (bounce.userlistmail.com, gmail.com) where DMARC has to rely on DKIM alignment.
DKIM alignment: all 24 observed emails sign with a domain aligned with sparkloop.app (sparkloop.app). DKIM authenticates the visible From — supports DMARC directly.
TLS: modern — 82% TLS 1.3 (across 11 sends).
Delivery: fast — 100% of emails in the last 7 days arrive in under 10 seconds (across 4 sends).
Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).
Userlist 8 Amazon SES 1ESPs 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: sparkloop.app, ckespa.sparkloop.app, bounce.userlistmail.com, gmail.com, pm-bounces.sparkloop.app, bounce.sparkloop.app
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 | 25 | 73.5% |
| promotions | 9 | 26.5% |
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 % |
|---|---|---|---|---|---|
| Amazon SES | 1 | 100.0% | 0.0% | 0.0% | |
| Kit | 16 | 62.5% | 37.5% | 0.0% | |
| Postmark | 3 | 100.0% | 0.0% | 0.0% | |
| Userlist | 8 | 75.0% | 25.0% | 0.0% |
Weekly 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 sparkloop.app has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Placement | Reputation |
|---|---|---|---|---|
| 149.72.176.45 | o30.ck.m.convertkit.com |
4 | 2 | Check → |
| 168.245.126.179 | o4.ck.m.convertkit.com |
3 | — | Check → |
| 149.72.193.89 | o48.ck.n.convertkit.com |
3 | — | Check → |
| 142.0.180.249 | out80-249.userlistmail.com |
3 | 1 | Check → |
| 149.72.39.237 | o38.ck.n.convertkit.com |
2 | — | Check → |
| 159.183.200.47 | o51.ck.n.convertkit.com |
2 | — | Check → |
| 149.72.60.6 | o47.ck.n.convertkit.com |
2 | — | Check → |
| 192.254.115.187 | o42.ck.n.convertkit.com |
2 | 2 | Check → |
| 168.245.5.113 | o20.ck.n.convertkit.com |
2 | 2 | Check → |
| 142.0.178.46 | out78-46.userlistmail.com |
1 | — | Check → |
| 50.31.205.220 | mta220-ab1.mtasv.net |
1 | — | Check → |
| 54.240.42.184 | a42-184.smtp-out.amazonses.com |
1 | — | Check → |
| 104.245.209.215 | mta215a-ord.mtasv.net |
1 | — | Check → |
| 142.0.178.45 | out78-45.userlistmail.com |
1 | — | Check → |
| 149.72.158.9 | o27.ck.m.convertkit.com |
1 | 1 | Check → |
| 104.245.209.212 | mta212a-ord.mtasv.net |
1 | 1 | Check → |
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
sparkloop.app | Kit 22 Userlist 8 Postmark 3 Amazon SES 1 |
