Missed email – Is it possible to log in a table?

Hi.

We have a little travel agency since 9 years. Since the begeinning we are using Contact Form 7, still on the same way.

We have 2 forms on our website :

1 – contact
2 – booking

When someone fill a form and valid it, a copy is sent to the client, a different copy is sent to us.
Our hosting is the same for the website than our email (Infomaniak.ch ).

Since few weeks, I received 3 messages on our socials networks from people who didn’t receive any answer from us. They received the copy on their email, but we didn’t received any copy. In the same time, we continue to receive request from other persons.

We don’t have any antispam.
I contacted yesterday Infomaniak about this, but not yet any answer…

My questions is :
Is it possible to log in a table each person who fill and valid a form? To follow what is happening, and mostly to don’t miss any booking request?

Thank you.

Jey