How to force manual retrieving of mail with automatic sending

I have been trying to fiddle with settings to no avail. I want to reduce incoming distraction while still remaining connected and sending emails. What I want to do is:

  • Disable all automatic mail retrieval and only retrieve mail when I choose to, by pressing the button.
  • Continue to have my sent emails send when I press send. I don’t want them piling up until being manually sent later, such as if I go offline entirely.

This would seem to be a basic feature to stop to flood of incoming email while still allowing me to be online and send promptly. But I can’t find a way to do it.