Supabase uses Customer.io for marketing email and Postmark for transactional/notifications. They rank #5,919 in the Tranco list of most-popular domains. We've also observed sends via Amazon SES. Their email authentication setup is solid (score 85/100).
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.
SPF / DKIM / DMARC above reflect the last 2 emails we've observed. DMARC policy is read live from DNS.
DMARC reports sent to DMARC Digests. Policy
p=reject means receivers actively block or quarantine spoofed mail.
SPF alignment: all 21 observed emails use a return-path aligned with supabase.com (pm-bounces.supabase.com, cio127276.supabase.com, bounce.supabase.com). SPF authenticates the visible From — supports DMARC directly.
DKIM alignment: all 16 observed emails sign with a domain aligned with supabase.com (supabase.com, cio127276.supabase.com). DKIM authenticates the visible From — supports DMARC directly.
TLS: 67% TLS 1.3, 33% TLS 1.2 (across 6 sends).
Delivery: fast — 100% of emails in the last 7 days arrive in under 10 seconds (across 2 sends).
Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).
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: supabase.com, bounce.supabase.com, pm-bounces.supabase.com, cio127276.supabase.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 | 22 | 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 % |
|---|---|---|---|---|---|
| Amazon SES | 1 | 100.0% | 0.0% | 0.0% | |
| Customer.io | 7 | 100.0% | 0.0% | 0.0% | |
| Postmark | 13 | 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 supabase.com has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Placement | Reputation |
|---|---|---|---|---|
| 198.244.52.3 | a3.a355d2fe.use4.send.mailgun.net |
5 | 1 | Check → |
| 104.245.209.201 | mta201a-ord.mtasv.net |
3 | — | Check → |
| 50.31.205.5 | mta5-ab1.mtasv.net |
2 | — | Check → |
| 159.112.241.98 | v598.v5c4dda55.use4.send.mailgun.net |
2 | — | Check → |
| 104.245.209.231 | mta231b-ord.mtasv.net |
2 | — | Check → |
| 104.245.209.237 | mta237b-ord.mtasv.net |
2 | — | Check → |
| 54.240.48.101 | a48-101.smtp-out.amazonses.com |
1 | — | Check → |
| 50.31.205.19 | mta19-ab1.mtasv.net |
1 | — | Check → |
| 50.31.205.33 | mta33-ab1.mtasv.net |
1 | — | Check → |
| 50.31.205.207 | mta207-ab1.mtasv.net |
1 | — | Check → |
| 50.31.205.204 | mta204-ab1.mtasv.net |
1 | — | Check → |
| 104.245.209.203 | mta203a-ord.mtasv.net |
1 | 1 | Check → |
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
supabase.com | Postmark 14 Customer.io 7 Amazon SES 1 |
