BuddyPress.org

I am using WordPress 4.1 and BuddyPress 2.1.1, the latest versions of both. I use hostinger.co.uk as my webhost. It has always been satisfactory, except the server resources are a bit limited. However, the email activation functions are not working. Emails are not being sent to new registrations, so people cannot activate their accounts themselves, and I have to manually go in and activate it for them. This is very distracting and time consuming, especially when I have to wade through dozens of span accounts to find one legit user. My guess is that it is because of my webhost, but I am not sure how to resolve the issue. Any help would be great.