Hello Pankaj !
Thank you for your reply. I went last week into a lots of troubles with some hackers using bots to put my website off by the contact form. I end up desactivating the contact form.
Concerning the Joomla version that I am using, I did not update because I got some modules that were not working anymore with some updates. So I keep using this version that you can see.
Please find below my administrator login :
[edited by moderator]
With regards.