It shouldn’t happen since feed by mail just generates automatically an email which is then sent with the same delivery engine used for standard email. Have you the same issue with regular email? How did you find those duplicates?
when i am subscribed to the list as a user, when newsletter is send i get it 2 times. This happens to all users. Also, in the admin, in feed by email, in “Emails” tab i see that everything is send twice. Please check this screeshot
Also, i dont have the same issue when sending regular emails.
Uhm, not good, it seems your installation has two scheduked generation tasks. Try to deactivate the feed by mail and then reactivate. You should even installa cron manager to look into this problem, since we need to discover is there are actually two schedules tasks.
Install Advanced Cron manager plugin so we can have a table of all scheduled tasks.
Hi your cron is ok. I don’t know why wordpress is firing the task two times… usually it can happen if you have more than one external cron call setup or if you have the blog installed in a cluster of server.