This extension uses several external services to provide the functionality. The privacy policy of these services is as follows:

CloudFlare DNS

Cloudflare DNS is used to resolve BIMI records associated with email addresses.
Their privacy policy can be found here.

In short, Cloudflare's 1.1.1.1 public DNS resolver, developed with
APNIC, is designed for privacy by encrypting DNS requests to prevent
spying, not selling or using personal data for advertising, anonymizing IP
addresses, retaining data only for operational purposes and limited time,
and allowing APNIC access to anonymized logs for research.

DuckDuckGo
DuckDuckGo is used to retrieve website icons.

Their privacy policy can be found here and specifically for the
icons here.

Gravatar
Gravatar is used to retrieve user avatars.

Their privacy policy can be found here.