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Stainless

stainless.com
🏆Rank #672,851 🏷 Manufacturing 🇺🇸United States

Stainless uses Postmark as their primary email service provider. They rank #672,851 in the Tranco list of most-popular domains. Their email authentication setup is good (score 80/100). Missing: one-click unsubscribe.

Transactional ESPPostmark
Total observations7
Active days6
Avg per active day1.2
Last activity📬 Active · 10 days ago
Cadence~weekly
Compare Stainless with another brand:

Email setup 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.

Solid setup, room to improve
Most authentication signals are present. A couple of pieces would tighten things up.
80/100
SPF
pass
DKIM
pass
DMARC
pass (quarantine)
BIMI
none
Unsubscribe
missing
SPF lookups 3/10

SPF / DKIM / DMARC above reflect the last 2 emails we've observed. DMARC policy is read live from DNS.

Authentication

DMARC reports sent to cloudflare.net. Policy p=quarantine means receivers actively block or quarantine spoofed mail.

SPF alignment: all 7 observed emails use a return-path aligned with stainless.com (pm-bounces.stainless.com). SPF authenticates the visible From — supports DMARC directly.

DKIM alignment: all 4 observed emails sign with a domain aligned with stainless.com (stainless.com). DKIM authenticates the visible From — supports DMARC directly.

Other ESPs detected

Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).

None — only the primary ESP(s) shown above

Confirmed senders

ESPs 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.

Postmark ✓ confirmed

Other SPF authorizations

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.

Google Workspace HubSpot

Probed: stainless.com, pm-bounces.stainless.com

Where emails landed (Gmail)

Folder distribution across all emails from this brand observed in Gmail inboxes. High inbox % = good deliverability; spam appearances are the headline signal.

FolderCountShare
inbox 7 100.0%

Placement by ESP

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 %
Postmark 7
100.0% 0.0% 0.0%

ESP activity over time

May 13 – Jun 21, 2026 · 5 days with sends

Daily observations per ESP. Brands often run multiple ESPs concurrently — marketing on one, transactional on another — so this chart shows usage rather than switches.

3 0 Postmark: 3 (2026-05-13)3Postmark: 1 (2026-06-05)1Postmark: 1 (2026-06-13)1Postmark: 1 (2026-06-20)1Postmark: 1 (2026-06-21)105/1305/1705/2105/2505/2906/0206/0606/1006/1406/1806/21
Postmark

Similar brands using Postmark

Sending IPs

IP addresses stainless.com has been observed sending from, and where their mail landed in Gmail.

IPHostnameObsPlacementReputation
104.245.209.202 mta202a-ord.mtasv.net 1 Check →
104.245.209.201 mta201a-ord.mtasv.net 1 Check →
104.245.209.231 mta231b-ord.mtasv.net 1 Check →
50.31.205.204 mta204-ab1.mtasv.net 1 Check →
50.31.205.205 mta205-ab1.mtasv.net 1 Check →
104.245.209.200 mta200a-ord.mtasv.net 1 1 Check →
104.245.209.203 mta203a-ord.mtasv.net 1 1 Check →

Sending domains

DomainESPs detectedDelivery (7d)
stainless.comPostmark 7