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Userback

userback.io
🏆Rank #29,406 🏷 SaaS 🇺🇸United States

Userback uses Mailgun as their primary email service provider. They rank #29,406 in the Tranco list of most-popular domains. Their email authentication setup is good (score 73/100). Missing: DMARC enforcement.

Transactional ESPMailgun
Total observations5
Active days5
Avg per active day1.0
Last activity⏸ Slowing · 3 weeks ago
Cadence~weekly
Compare Userback with another brand:

Email setup 73/100

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.
73/100
SPF
pass
DKIM
pass
DMARC
pass (none)
BIMI
none
Unsubscribe
one-click
SPF lookups 5/10
Authentication

DMARC reports sent to userback.io. Policy p=none is monitor-only — receivers won't act on spoofing yet.

SPF alignment: all 5 observed emails use a return-path aligned with userback.io (outbound.intercom.userback.io, mt.userback.io). SPF authenticates the visible From — supports DMARC directly.

DKIM alignment: all 4 observed emails sign with a domain aligned with userback.io (userback.io, mt.userback.io). 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).

Intercom 4

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.

Mailgun ✓ confirmed Intercom ✓ via SparkPost

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.

Elastic Email Google Workspace HubSpot SparkPost

Probed: userback.io, outbound.intercom.userback.io, mt.userback.io

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 5 100.0%

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 %
Intercom 4
100.0% 0.0% 0.0%
Mailgun 1
100.0% 0.0% 0.0%

ESP activity over time

Jun 4 – Jun 7, 2026 · 4 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.

1 0 Intercom: 1 (2026-06-04)1Intercom: 1 (2026-06-05)1Mailgun: 1 (2026-06-06)1Intercom: 1 (2026-06-07)106/0406/0506/0606/07
Intercom Mailgun

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Sending IPs

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

IPHostnameObsReputation
192.174.84.116 mta-174-84-116.intercom.com.sparkpostmail.com 2 Check →
192.174.84.120 mta-174-84-120.intercom.com.sparkpostmail.com 1 Check →
204.220.184.33 k33.kb8c70eb.use4.send.mailgun.net 1 Check →
192.174.84.115 mta-174-84-115.intercom.com.sparkpostmail.com 1 Check →

Per-IP inbox / promotions / spam is being collected and will appear here as new emails are observed.

Sending domains

DomainESPs detectedDelivery (7d)
userback.ioIntercom 4 Mailgun 1