Show error message if plugin cannot be enabled

[darrylhein]

After a good 30+ minutes, we finally found the FAQ item stating that the plugin is not shown if another plugin is using wp_mail. Would it instead be possible to still show the menu item with a message stating why it's not enabled/being used?

[pgraham3]

@darrylhein Yes this should definitely be improved - sorry for the trouble there. I think preventing the plugin's activation altogether if a conflict is detected may be the best option for ensuring folks don't try to use it while another plugin is also overriding wp_mail.