[Plugin: ALO EasyMail Newsletter] some recipients wont get e-mail and some get multiple times

At first, you can set up a lower max number of emails per batch (e.g. 20 or 30): https://www.eventualo.net/blog/2012/04/easymail-2-4-7/
Otherwise, there could be a conflict with another plugin. I don’t know issues with plugins installed on your blog. You can make some researches about other plugins versus WP cron or other newsletter plugin… If you find some issues and fixes please share them.