How to forward mail to another account

I have a WordPress-website with a ‘Contact Me’ page made with “WPForms Lite”. I have tried it out with V1.5.9.1 and V1.5.9.5 (i.e. the most recent version at the time of this writing).

I am experiencing problems with receiving mail from my contact page.
I want the data that has been entered in the ‘Contact Me’ page to be sent to my hotmail account (e.g. [email protected]). I entered this e-mail address in
WordPress Dashboard: WPForms > Settings > Notifications > Send To Email Address
But nothing makes it to the Inbox of [email protected].

I have read a lot and tried even more, but none of it works. None of the attempts were ever sent to my hotmail-account.

To find out what the problem is, I have tried a different approach.
1. First I have set up my ‘Contact Me’ page to send the data to my website’s mail address (e.g. [email protected]). By the way, this is ‘Roundcube’.
This works: when I fill out the ‘Contact Me’ page on my website, the data is sent correctly to the mail-address of my website.

2. Then I wanted this mail to be sent to my hotmail-account. So I set up forwarding.
This I did in my website’s ‘DirectAdmin’. Here a ‘Forwarder’ has been added: [email protected] -> [email protected]
Now, when I fill out my the ‘Contact Me’ page on my website, the data is sent correctly to the mail-address of my website. But I do not receive it on my Hotmail-account.
3. When I send an e-mail to [email protected] from any mail-account, then the ‘forwarder’ works fine and I do receive it correctly on [email protected].
4. When I send an e-mail directly from within ‘Roundcube’ to my hotmail-account, I do receive this correctly on [email protected].

5. After this, I thought that perhaps Hotmail was stopping the mails from arriving in the Inbox of [email protected].
Therefore I ‘whitelisted’ the address [email protected] in my hotmail-account.
6. No improvement: when I fill out my the ‘Contact Me’ page on my website, the data is sent correctly to the mail-address of my website. But I do not receive it on my Hotmail-account. Just as before.
7. When I forward the individual e-mail (that came from my Contact-page) in [email protected] to [email protected], it is delivered correctly on [email protected].

I only know some very basics about e-mail. So after trying out the above, I am stuck.

To me, all this seems as if something is wrong in some deep-deep properties/settings of the e-mail on my website.
I have read something somewhere(but I cannot not find that any more) that if some ‘from’-parameter in an e-mail does not match some other parameter, an e-mail could be seen as ‘spam’ and either be delivered into the Spam-box or not even be delivered at all.

Can anyone help me solve the above situation so that I can get the data from my ‘Contact-page’ to my hotmail-account (either directly or by forwarding it via [email protected])?

Any help is very much appreciated.
Thanks in advance.

P.S. I hope I put this post in the right sub-forum.

The page I need help with: [log in to see the link]