Email Issues

I really don’t know where to begin. I have been using my WordPress site for many months now and everything has been working fine. I downloaded a new plugin yesterday and since then have not been able to send email from the site. This means that all of the forms I have on my page have error messages. I contacted the person who made the plugin and he helped me to look at the site and saw that everything looks fine within the site, just that the wordpress installation is no longer sending emails. I really know nothing about any of this, so I would appreciate any help I could possibly get. If you need me to post something, please tell me and I will do it. The site is https://www.customizedweddingcreations.com. Thanks.

Cherin