Make email work on form submission wtih djangocms 3.11 and python 3.7

[tofbang]

After installing correctly the plugin, and some small changes (like static instead of staticfiles in templates), the form submission was successful, but i didn't receive the mail.
My first research led me to verify the mime structure of the mail by adding an 'alternative/mixed' level,

In fine, the problem was not here and it seems characters from mails template were the reason of the failed send.

After a lot of frustration, i have found that the ' Send via' line in hmtl an text email template was the cause.
Apparently the 'http' mentionned is not appreciated.

So, i remove this line from email.thml:
{% trans 'Sent via' %} {{ request.get_host }}{{ referrer }}
And this line in email.txt:
{% trans 'Sent via' %} http://{{ request.get_host }}

Now it works perfectly !