We may not be able to help here since we don't have access to the mail server. There are other users here of HostforWeb. If you had made your title more descriptive, such as "Can not send emails on HostforWeb" then other hostforweb users may have come in and offer their advice. I thought HostforWeb is listed as a Dolphin host; if so, then they should get off their arses and tell you why it may not be working.
The easiest solution for you may be to install the SMTP module and use a third party mail service.
Note: they are and this is the advertisement on Boonex.
Take advantage of HostForWeb's experience in hosting thousands of Dolphin based websites! We'll be here each step of the way as you create your new Social Community website. HFW is the first and the most experienced hosting provider for BoonEx Dolphin.
So they should be eager to help you fix the issue.