Mail Proxy Servers

What is the Yahoo Mail Proxy?

Yahoo Mail Proxy is a content fetch proxy that retrieves the page content of URLs that are embedded within emails sent to Yahoo Mail users. Having the content displayed through the proxy improves the security for our users while reducing overall network usage.

How does the Yahoo Mail Proxy identify itself?

Web site access for Yahoo Mail Proxy is identified by “YahooMailProxy” User-agents. The full user-agent value you'll see in your access logs are:

User agent
YahooMailProxy; https://senders.yahooinc.com/mail-proxy-servers

IPs used by Yahoo Mail Proxy

Requests to images and potentially other assets embedded in emails sent to our users will come from the following IPs. We recommend not to rate-limit or block those to ensure recipients of your emails do not have a broken experience.

IPv4
27.XXX - 98.XXX
27.123.32.0/19
67.195.0.0/16
69.147.64.0/18
87.248.96.0/19
98.138.0.0/15
106.XXX - 216.XXX
106.10.128.0/17
115.178.0.0/20
119.161.0.0/19
200.152.160.0/20
202.43.192.0/19
209.73.160.0/19
212.82.96.0/19
216.115.96.0/20
IPv6
2001:XXX - 2a00:XXX
2001:4998::/32
2406:2000::/32
2406:6e00::/32
2804:1bc::/32
2a00:1288::/32

In addition you can find the latest list of IPs published here