> This page is part of the [Customer.io documentation](https://docs.customer.io). For the complete index, see [llms.txt](https://docs.customer.io/llms.txt).
> Last updated: April 23, 2026

# Allowlist our IP addresses

If you use a firewall or an allowlist, you may need to allow traffic from our IP addresses to support traffic from Customer.io based on the features you use.

If you use a custom SMTP server, webhooks, Reverse ETL, our Salesforce integration, or an outgoing data warehouse integration, you may need to allow our IP addresses to support traffic from Customer.io.

Some IP addresses depend on your account region.

Email (Custom SMTP) and Webhook IP Addresses

US Region

EU Region

35.188.196.183

34.76.143.229

104.198.177.219

34.78.91.47

104.154.232.87

34.77.94.252

130.211.229.195

35.187.188.242

104.198.221.24

34.78.122.90

104.197.27.15

35.195.137.235

35.194.9.154

130.211.108.156

104.154.144.51

104.199.50.18

104.197.210.12

34.78.44.80

35.225.6.73

35.205.31.154

136.111.237.157

34.10.127.179

Reverse ETL IP Addresses (data-in)

US Region

EU Region

34.29.50.4

34.22.168.136

35.222.130.209

34.78.194.61

34.122.196.49

104.155.37.221

Salesforce IP Addresses

IP Addresses

34.29.50.4

35.222.130.209

Data Warehouse IP Addresses (data-out)

US Region

EU Region

34.71.192.245

34.118.255.179

35.188.196.183

34.76.143.229

104.198.177.219

34.78.91.47

35.184.88.76

35.187.55.80

34.72.101.57

104.199.99.65

34.123.199.33

34.76.81.2

35.222.137.61

34.77.146.181

34.68.113.63

34.140.234.108

35.240.84.170

35.195.54.15

34.38.105.52

104.155.66.230

34.76.119.61

34.140.67.73

34.78.74.81