Newsletter platform with paid subscriptions.
Substack is the 9th most popular marketing ESP we track.
Detected by 203 distinct extension users.
Distribution of brands using Substack by industry. Helps you gauge whether this ESP is popular with businesses similar to yours. Brands tagged in two industries are counted in both.
Based on 237 of 348 brands tagged (68% coverage). Industries assigned automatically using AI; not every brand is tagged yet.
Where this ESP's emails land in Gmail. Each brand counted once (average of per-brand percentages) so a single high-volume sender can't dominate. Spam placement is mostly driven by the sender (list quality, content, complaint rate). This number reflects both the ESP's infrastructure AND the kind of senders who choose it — not just deliverability quality.
By volume: inbox 2,195 · promotions 119 · spam 7 (2,321 emails observed)
Percentages are averaged per brand (each counted once) across 85 brands using Substack with at least 5 placement observations each.
Underlying transactional infrastructure Substack routes through, detected from the sender hostname (PTR record) on each email's Received header. Bigger sample → more accurate.
344 as their primary ESP, the rest send transactional or secondary email through it. Primary users are listed first, then secondary.
| Brand | Role | Obs | Spam | Last seen |
|---|---|---|---|---|
|
Substack
substack.com
|
primary | 41 | 0.0% | 2026-06-30 |
|
1800dtc
1800dtc.substack.com
|
primary | 13 | 0.0% | 2026-06-25 |
|
Aakashgupta
aakashgupta.substack.com
|
primary | 1 | — | 2026-05-19 |
|
Aaronparnas
aaronparnas.substack.com
|
primary | 2 | — | 2026-06-09 |
|
Abhiyadav
abhiyadav.substack.com
|
primary | 4 | 0.0% | 2026-06-14 |
|
Accessfuel
accessfuel.substack.com
|
primary | 2 | — | 2026-06-04 |
|
Accionables
accionables.substack.com
|
primary | 4 | 0.0% | 2026-06-11 |
|
Adcatalyst
adcatalyst.substack.com
|
primary | 1 | — | 2026-05-19 |
|
Admiredleadership
admiredleadership.substack.com
|
primary | 19 | 0.0% | 2026-06-29 |
|
Afterschool
afterschool.substack.com
|
primary | 6 | 0.0% | 2026-06-29 |
|
Aireadycmo
aireadycmo.substack.com
|
primary | 3 | 0.0% | 2026-06-23 |
|
Airepo
airepo.substack.com
|
primary | 3 | 0.0% | 2026-06-05 |
|
Aiuncovering
aiuncovering.substack.com
|
primary | 1 | — | 2026-06-05 |
|
Alexmhsmith
alexmhsmith.substack.com
|
primary | 17 | 0.0% | 2026-06-24 |
|
Algotradealert
algotradealert.substack.com
|
primary | 19 | 0.0% | 2026-06-18 |
|
Almosttimely
almosttimely.substack.com
|
primary | 6 | 0.0% | 2026-06-07 |
|
Altsummit
altsummit.substack.com
|
primary | 1 | — | 2026-06-26 |
|
Anntelnaes
anntelnaes.substack.com
|
primary | 2 | — | 2026-05-28 |
|
Appeconomyinsights
appeconomyinsights.substack.com
|
primary | 2 | — | 2026-06-16 |
|
Aprildunford
aprildunford.substack.com
|
primary | 1 | — | 2026-06-23 |
|
Arbitrageandy
arbitrageandy.substack.com
|
primary | 4 | 0.0% | 2026-06-23 |
|
Arkticfox
arkticfox.substack.com
|
primary | 1 | — | 2026-06-03 |
|
Askachiefofstaff
askachiefofstaff.substack.com
|
primary | 4 | 0.0% | 2026-06-23 |
|
Austinkleon
austinkleon.substack.com
|
primary | 2 | — | 2026-06-02 |
|
Automatter
automatter.substack.com
|
primary | 1 | — | 2026-06-08 |
|
Barbarabramo
barbarabramo.substack.com
|
primary | 16 | 0.0% | 2026-06-28 |
|
Bcreator
bcreator.substack.com
|
primary | 1 | — | 2026-06-17 |
|
Beausociety
beausociety.substack.com
|
primary | 2 | — | 2026-06-26 |
|
Bensbites
bensbites.substack.com
|
primary | 3 | 0.0% | 2026-06-02 |
|
Berkeleyrdi
berkeleyrdi.substack.com
|
primary | 1 | — | 2026-05-27 |
|
Betteryounotes
betteryounotes.substack.com
|
primary | 1 | — | 2026-06-21 |
|
Bigthinkmedia
bigthinkmedia.substack.com
|
primary | 11 | 0.0% | 2026-06-17 |
|
Bitecode
bitecode.substack.com
|
primary | 1 | — | 2026-06-21 |
|
Bostonmartialartscenter
bostonmartialartscenter.substack.com
|
primary | 1 | — | 2026-06-09 |
|
Botharetrue
botharetrue.substack.com
|
primary | 1 | — | 2026-06-25 |
|
Brandtribe
brandtribe.substack.com
|
primary | 12 | 0.0% | 2026-06-26 |
|
Brianmaierhofer
brianmaierhofer.substack.com
|
primary | 1 | — | 2026-05-17 |
|
Briantylercohen
briantylercohen.substack.com
|
primary | 1 | — | 2026-06-14 |
|
Buildwithaiclub418
buildwithaiclub418.substack.com
|
primary | 1 | — | 2026-06-08 |
|
Burk
burk.substack.com
|
primary | 1 | — | 2026-05-19 |
|
Burnedhaystack
burnedhaystack.substack.com
|
primary | 4 | 0.0% | 2026-06-20 |
|
Bytebytego
bytebytego.substack.com
|
primary | 12 | 0.0% | 2026-06-27 |
|
Cafecondigital
cafecondigital.substack.com
|
primary | 4 | 0.0% | 2026-06-29 |
|
Cannonballgtm
cannonballgtm.substack.com
|
primary | 5 | 0.0% | 2026-06-24 |
|
Cantadorafieldnotes
cantadorafieldnotes.substack.com
|
primary | 2 | — | 2026-06-01 |
|
Careerhappiness
careerhappiness.substack.com
|
primary | 12 | 0.0% | 2026-06-04 |
|
Carvalhando
carvalhando.substack.com
|
primary | 1 | — | 2026-06-02 |
|
Cashflowdiary
cashflowdiary.substack.com
|
primary | 26 | 0.0% | 2026-06-28 |
|
Chantellemorrison
chantellemorrison.substack.com
|
primary | 1 | — | 2026-06-05 |
|
Charliehills
charliehills.substack.com
|
primary | 2 | — | 2026-06-21 |
|
Chrisgeidner
chrisgeidner.substack.com
|
primary | 1 | — | 2026-06-17 |
|
Chuckescapes
chuckescapes.substack.com
|
primary | 2 | — | 2026-05-29 |
|
Citationsplease
citationsplease.substack.com
|
primary | 1 | — | 2026-06-05 |
|
Claudedesktop
claudedesktop.substack.com
|
primary | 2 | — | 2026-06-01 |
|
Claudenotebook
claudenotebook.substack.com
|
primary | 1 | — | 2026-06-06 |
|
Cloudedjudgement
cloudedjudgement.substack.com
|
primary | 4 | 0.0% | 2026-06-26 |
|
Comocomiclub
comocomiclub.substack.com
|
primary | 2 | — | 2026-05-21 |
|
Contentevc
contentevc.substack.com
|
primary | 4 | 0.0% | 2026-06-16 |
|
Coreyhinde
coreyhinde.substack.com
|
primary | 1 | — | 2026-06-23 |
|
Cosasdefreelance
cosasdefreelance.substack.com
|
primary | 4 | 0.0% | 2026-06-18 |
|
Crookedmedia
crookedmedia.substack.com
|
primary | 9 | 0.0% | 2026-06-22 |
|
Dailyheadlines
dailyheadlines.substack.com
|
primary | 20 | 0.0% | 2026-06-29 |
|
Danabramov
danabramov.substack.com
|
primary | 3 | 0.0% | 2026-06-19 |
|
Danaherra
danaherra.substack.com
|
primary | 1 | — | 2026-05-19 |
|
Danielcasal
danielcasal.substack.com
|
primary | 1 | — | 2026-05-25 |
|
Darkopavic
darkopavic.substack.com
|
primary | 1 | — | 2026-06-24 |
|
Darrellalfonso
darrellalfonso.substack.com
|
primary | 10 | 0.0% | 2026-06-26 |
|
Daveshap
daveshap.substack.com
|
primary | 1 | — | 2026-05-26 |
|
Davidfastuca
davidfastuca.substack.com
|
primary | 4 | 0.0% | 2026-06-17 |
|
Davidlebovitz
davidlebovitz.substack.com
|
primary | 1 | — | 2026-06-13 |
|
Dawestheband
dawestheband.substack.com
|
primary | 5 | 0.0% | 2026-06-25 |
|
Demesio
demesio.substack.com
|
primary | 1 | — | 2026-05-27 |
|
Diannealter
diannealter.substack.com
|
primary | 1 | — | 2026-06-12 |
|
Digitaldeepakblog
digitaldeepakblog.substack.com
|
primary | 3 | 0.0% | 2026-06-08 |
|
Dowhatworks
dowhatworks.substack.com
|
primary | 4 | 0.0% | 2026-06-26 |
|
Elenaverna
elenaverna.substack.com
|
primary | 11 | 0.0% | 2026-06-25 |
|
Elfbeauty
elfbeauty.substack.com
|
primary | 1 | — | 2026-06-16 |
|
Embedded
embedded.substack.com
|
primary | 1 | — | 2026-06-17 |
|
Engineerofdata
engineerofdata.substack.com
|
primary | 2 | — | 2026-06-16 |
|
Enzocolucci
enzocolucci.substack.com
|
primary | 1 | — | 2026-06-01 |
|
Esgfitness
esgfitness.substack.com
|
primary | 4 | 0.0% | 2026-06-18 |
|
Estoicismomaestro
estoicismomaestro.substack.com
|
primary | 3 | 0.0% | 2026-06-08 |
|
Eveliosilvera
eveliosilvera.substack.com
|
primary | 2 | — | 2026-06-08 |
|
Excellentprompts
excellentprompts.substack.com
|
primary | 1 | — | 2026-06-01 |
|
Failagain
failagain.substack.com
|
primary | 1 | — | 2026-06-03 |
|
Faroljornalismo
faroljornalismo.substack.com
|
primary | 8 | 0.0% | 2026-06-26 |
|
Figsinwintertime
figsinwintertime.substack.com
|
primary | 17 | 0.0% | 2026-06-30 |
|
Filtercoffee
filtercoffee.substack.com
|
primary | 2 | — | 2026-05-20 |
|
Floatvibes
floatvibes.substack.com
|
primary | 3 | 0.0% | 2026-06-10 |
|
Floriangrummes
floriangrummes.substack.com
|
primary | 2 | — | 2026-06-29 |
|
Foreignkey
foreignkey.substack.com
|
primary | 4 | 0.0% | 2026-06-18 |
|
Freelancejobsnetwork
freelancejobsnetwork.substack.com
|
primary | 24 | 0.0% | 2026-06-23 |
|
Freelancejobsuk
freelancejobsuk.substack.com
|
primary | 23 | 0.0% | 2026-06-26 |
|
Freyaindia
freyaindia.substack.com
|
primary | 1 | — | 2026-05-28 |
|
Fromthefrontlines
fromthefrontlines.substack.com
|
primary | 4 | 0.0% | 2026-06-25 |
|
Fromvanessasdesk
fromvanessasdesk.substack.com
|
primary | 4 | 0.0% | 2026-06-14 |
|
Galiza
galiza.substack.com
|
primary | 1 | — | 2026-06-16 |
|
Garymarcus
garymarcus.substack.com
|
primary | 1 | — | 2026-05-22 |
|
Georgesaunders
georgesaunders.substack.com
|
primary | 2 | — | 2026-05-20 |
|
Gigglysquad
gigglysquad.substack.com
|
primary | 1 | — | 2026-06-17 |
IPs we've observed sending via Substack. "Brands" = distinct brands seen on each IP; "Placement" = where those emails landed in Gmail (inbox / promotions / spam). Click "reputation" to check the IP on Cisco Talos.
| IP | Hostname | Brands | Obs | Placement | Reputation |
|---|---|---|---|---|---|
| 159.112.244.47 | v547.v5375b7fa.use4.send.mailgun.net |
20 | 32 | 6 | Check → |
| 161.38.199.249 | mg-199-249.static.mg-d0.substack.com |
19 | 32 | 9 | Check → |
| 159.112.244.54 | v554.v5375b7fa.use4.send.mailgun.net |
15 | 31 | 7 | Check → |
| 69.72.47.244 | mg-47-244.substack.com |
18 | 30 | 9 | Check → |
| 159.112.244.32 | v532.v5375b7fa.use4.send.mailgun.net |
19 | 29 | 6 | Check → |
| 159.112.244.56 | v556.v5375b7fa.use4.send.mailgun.net |
18 | 29 | 8 | Check → |
| 161.38.194.182 | mg-194-182.static.mg-d0.substack.com |
17 | 28 | 5 | Check → |
| 159.112.244.6 | v56.v5375b7fa.use4.send.mailgun.net |
16 | 28 | 5 | Check → |
| 159.112.244.45 | v545.v5375b7fa.use4.send.mailgun.net |
17 | 28 | 4 | Check → |
| 159.112.244.41 | v541.v5375b7fa.use4.send.mailgun.net |
17 | 27 | 6 | Check → |
| 69.72.32.112 | mg-32-112.substack.com |
16 | 27 | 7 | Check → |
| 161.38.197.117 | mg-197-117.substack.com |
17 | 26 | 10 | Check → |
| 159.112.244.10 | v510.v5375b7fa.use4.send.mailgun.net |
18 | 25 | 4 | Check → |
| 161.38.202.253 | mg-202-253.substack.com |
16 | 25 | 3 | Check → |
| 159.112.244.12 | v512.v5375b7fa.use4.send.mailgun.net |
16 | 25 | 2 | Check → |
| 159.112.244.58 | v558.v5375b7fa.use4.send.mailgun.net |
13 | 25 | 3 | Check → |
| 159.112.244.59 | v559.v5375b7fa.use4.send.mailgun.net |
16 | 25 | 6 | Check → |
| 159.112.244.51 | v551.v5375b7fa.use4.send.mailgun.net |
18 | 25 | 4 | Check → |
| 159.112.244.44 | v544.v5375b7fa.use4.send.mailgun.net |
13 | 25 | — | Check → |
| 159.112.244.34 | v534.v5375b7fa.use4.send.mailgun.net |
16 | 24 | 10 | Check → |
| 159.112.244.5 | v55.v5375b7fa.use4.send.mailgun.net |
16 | 24 | 4 | Check → |
| 159.112.244.53 | v553.v5375b7fa.use4.send.mailgun.net |
17 | 24 | 3 | Check → |
| 161.38.195.184 | mg-195-184.substack.com |
16 | 24 | 6 | Check → |
| 159.112.244.46 | v546.v5375b7fa.use4.send.mailgun.net |
12 | 23 | 4 | Check → |
| 159.112.244.57 | v557.v5375b7fa.use4.send.mailgun.net |
14 | 23 | 5 | Check → |