claws-mail-libravatar 3.13.2-1ubuntu1 (s390x binary) in ubuntu xenial

 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.