Linode mail configuration with domain registered with godaddy

Hi,

I have recently moved my site from shared hosting to linode VM, after transfering the folders and database, I only changed the A record entry with linode's IP address. The site loads properly, the only problem is the wordpress doesnt generate any mails like from contact form, etc. The mail works good when you are directly sending it with gmail or outlook, just not with the wordpress conatct form.

What can be done for this issue???