vaportunidades on "[Plugin: MailPoet Newsletters (formerly Wysija)] Error Sending suscription emails"

Hello, i´ve been reported on two issues on my website.

1- My newsletter is not being sent to my subscribers since latest Update. (I have all my WP and plugs up to date). Aparently it is sending them (xxx of xxx sent) but i have 3 personal email adreses subscrbed to my web´s newsletter and im not recieving any newsletter emails.

2- I´ve been notified that confirmation email for new registered users are not being sent either. So they cannot log in to my web page.

Here is a link to my site

Please help me solve this issue.

Thanks a lot.

http://wordpress.org/plugins/wysija-newsletters/