Mail receiving messages more often than 'Every hour'
Have set Mail preferences to check for new messages 'Every hour' but they're coming through every few minutes. Any ideas why this is happening and how can I stop it?
Mail Version 11.5 (3445.9.1)
High Sierra 10.13.6
Thanks in advance.
MacBook Pro (15-inch Mid 2010), Mac OS X (10.6.8)