This plugin for the Claws Mail mailer allows retrieval of profile images from libravatar servers, either federated servers (running on sender's domain) or the main libravatar.org server.

Currently supports all default missing icon modes on libravatar.org service, and makes extensive use of disk caching to minimize the number of network requests.

Nevertheless, it may add several network requests per message, so if you're on a high latency network you may experience some delay displaying messages.