The plugin "Contact form" does not work!

Everytime when I want to send an email from tour page “Send enquiry” I have the message
“There was an error trying to send your message. Please try again later”. I tried to fix it, but it didnt work out. I tried to send email to support of this plugin, but this idiots can only say “read FAQ”, but in FAQ nothing for this problem. I tried to use SMPT, but…(( Please, help me! In the next message I’ll sent the all logs information for u