[Plugin: Custom Contact Forms] Emails are slow

I’m seeing the contact form submissions right away on the dashboard, but the people who are supposed to get the submissions are not getting the emails for hours or days. Any idea why that may be happening?

We have customers emailing us service calls on equipment via these forms so it is highly important to receive the emails quickly.

Thanks.

http://ww.wp.xz.cn/extend/plugins/custom-contact-forms/