Masterclass uses Iterable as their primary email service provider. They rank #10,322 in the Tranco list of most-popular domains. 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 8 emails we've observed. DMARC policy is read live from DNS.
DMARC reports sent to cloudflare.net. Policy
p=reject means receivers actively block or quarantine spoofed mail.
SPF alignment: 61% of observed emails use an aligned return-path (bounces.masterclass.com); the rest use third-party paths (amazonses.com) where DMARC has to rely on DKIM alignment.
DKIM alignment: all 18 observed emails sign with a domain aligned with masterclass.com (email.masterclass.com, masterclass.com). DKIM authenticates the visible From — supports DMARC directly.
TLS: 40% TLS 1.3, 60% TLS 1.2 (across 10 sends).
Delivery: fast — 100% of emails in the last 7 days arrive in under 10 seconds (across 8 sends).
Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).
None — only the primary ESP(s) shown aboveESPs 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: masterclass.com, amazonses.com, bounces.masterclass.com, email.masterclass.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 | 17 | 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 % |
|---|---|---|---|---|---|
| Iterable | 17 | 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 masterclass.com has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Placement | Reputation |
|---|---|---|---|---|
| 192.174.82.171 | mta-82-171.sparkpostmail.com |
8 | — | Check → |
| 192.174.82.170 | mta-82-170.sparkpostmail.com |
4 | 4 | Check → |
| 76.223.141.227 | c141-227.smtp-out.amazonses.com |
2 | — | Check → |
| 54.240.78.128 | a78-128.smtp-out.amazonses.com |
2 | 2 | Check → |
| 54.240.79.223 | a79-223.smtp-out.amazonses.com |
1 | — | Check → |
| 54.240.73.38 | a73-38.smtp-out.amazonses.com |
1 | 1 | Check → |
| 76.223.141.178 | c141-178.smtp-out.amazonses.com |
1 | 1 | Check → |
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
email.masterclass.com | Iterable 19 |
