EngageCustomer.com:

France, Germany and Spain all favour Apple devices when opening emails. 47% of emails in France are opened on an Apple device, 46% in Germany and 47% in Spain. Italy, in contrast, saw a decrease of 44% year-on-year in the use of iPhones to read emails. Yet Apple products remain the most used in Italy overall with 50% of emails opened on an Apple device, including a 15% increase in the use of iPad.

Even more remarkably:

Email open rates on Android devices dropped 30% year-on-year while total opens on iPads and iPhones increased by 18% and 5% respectively.

[Hat tip to Stu Mark]