Sometime Email not working using (mandrill account) laravel 5.1

I am using paid mandrill account to send mail over the internet using laravel 5.1 . It works fine while sending to gmail,yahoo accounts but problem is- sometimes it stopped sending email to domain email accounts like ledernytt.no, globdig.com sometime works fine.

I could not figure out the problem exactly, whether the problem in mail provider or on receiver side.

I am looking for long term solution, currently while rewrite the same code and works fine till next turn to be stopped.

via Chebli Mohamed