Exported cvs file not work

Support forumExported cvs file not work
md enam boss asked 4 years ago
When I export the appointment information to a CSV file, it generates an useless 1 bytes file… It opens in Excel, but shows no appointment info but instead shows three random characters in the first slot. This type error showing. TYPE: MAIL
ERRORS: {"wp_mail_failed":["Could not instantiate mail function."]} but email will sent to customer and admin . i have install wp-smtp plugin please help me sir