Thebulwark uses Substack as their primary email service provider. 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.
DMARC reports sent to Postmark DMARC. Policy
p=reject means receivers actively block or quarantine spoofed mail.
SPF alignment: observed emails use a third-party return-path (mg2.substack.com, mg-d0.substack.com, mg-d1.substack.com) — SPF passes there but doesn't align with thebulwark.substack.com, so DMARC has to rely on DKIM alignment.
DKIM alignment: observed emails sign with a third-party DKIM key (mg2.substack.com, mg-d1.substack.com, mg-d0.substack.com) — DKIM passes there but doesn't align with thebulwark.substack.com, so DMARC has to rely on SPF alignment.
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: thebulwark.substack.com, mg2.substack.com, mg-d0.substack.com, mg-d1.substack.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 | 31 | 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 % |
|---|---|---|---|---|---|
| Substack | 31 | 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 thebulwark.substack.com has been observed sending from, and where their mail landed in Gmail.
| IP | Hostname | Obs | Reputation |
|---|---|---|---|
| 159.112.244.13 | v513.v5375b7fa.use4.send.mailgun.net |
4 | Check → |
| 159.112.244.56 | v556.v5375b7fa.use4.send.mailgun.net |
2 | Check → |
| 161.38.199.249 | mg-199-249.static.mg-d0.substack.com |
2 | Check → |
| 161.38.202.170 | mg-202-170.substack.com |
2 | Check → |
| 159.112.244.20 | v520.v5375b7fa.use4.send.mailgun.net |
2 | Check → |
| 159.112.244.21 | v521.v5375b7fa.use4.send.mailgun.net |
2 | Check → |
| 161.38.202.253 | mg-202-253.substack.com |
1 | Check → |
| 159.112.244.57 | v557.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.51 | v551.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.34 | v534.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.47 | v547.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.4 | v54.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.59 | v559.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.19 | v519.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.3 | v53.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 69.72.47.221 | mg-47-221.substack.com |
1 | Check → |
| 159.112.244.44 | v544.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 161.38.195.184 | mg-195-184.substack.com |
1 | Check → |
| 159.112.244.42 | v542.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.7 | v57.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.55 | v555.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 161.38.197.117 | mg-197-117.substack.com |
1 | Check → |
| 159.112.244.32 | v532.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.33 | v533.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
| 159.112.244.16 | v516.v5375b7fa.use4.send.mailgun.net |
1 | Check → |
Per-IP inbox / promotions / spam is being collected and will appear here as new emails are observed.
| Domain | ESPs detected | Delivery (7d) |
|---|---|---|
thebulwark.substack.com | Substack 34 |