Unable to read data from the transport connection: net_io_connectionclosed

Question

Hello experts,

i have run into a problem today,as i get this error :

Unable to read data from the transport connection: net_io_connectionclosed

and i can't get the reason why?

Scenario :

i have two pages one is a contact us page and the other is a newsletter page, when i try to send an email from the contact us page the code works just fine else when i try to send from the newsletter page it gives me the above error so i don't get it??

i use the same function from the same class i only call it twice,yet it works on a page and doesn't for another.

Any advise?

thanks