Below is a list of IPs you can add to your firewall to send transactional emails through SMTP, Inbound processing, and Webhooks.
Outbound SMTP Servers
The IP addresses that Transactional and Broadcast messages are sent from.
-
- 50.31.156.96/27 (50.31.156.96 - 127) [Transactional]
- 104.245.209.192/26 (104.245.209.192 - 255) [Transactional]
- 50.31.205.204/30 (50.31.205.204 - 207) [Transactional]
-
50.31.205.0/24 (50.31.205.1 - 255) [Broadcast]
SMTP Endpoints
The IP endpoints for accessing SMTP outbound.
CIDR Blocks / Ranges
- 147.75.195.176/30 [147.75.195.176 - 147.75.195.179]
- 147.75.202.84/30 [147.75.202.84 -147.75.202.87]
- 147.75.205.84/30 [147.75.205.84 - 147.75.205.87]
- 52.79.88.220
- 54.180.186.193
- 34.249.162.51
- 52.208.184.61
- 63.35.51.189
- 3.208.98.158
- 3.93.205.235
- 3.95.122.1
- 3.208.98.158
- 3.93.205.235
- 3.95.122.1
- 13.209.189.43
- 15.164.159.110
- 52.208.94.138
- 52.210.34.36
- 54.77.222.65
Inbound SMTP Servers
These IPs are where Postmark's inbound MX record points.
- 13.58.75.120
- 52.36.8.247
- 18.221.96.15
- 34.211.250.229
- 34.211.88.250
- 18.221.180.145
- 52.210.157.196
- 52.213.211.243
- 52.51.73.41
- 13.125.126.102
- 3.34.204.228
- 3.34.213.247
- 107.22.71.110
- 52.2.5.255
- 72.44.42.226
Webhooks
These IPs apply for every webhook sent by Postmark (inbound, bounce, open, etc).
- 3.134.147.250
- 50.31.156.6
- 50.31.156.77
- 18.217.206.57