Redirecting Free emails to Gmail

You won’t find the email forwarding option when zimbra-free is in its default display mode, which is the pretentiously named "advanced AJAX".
Here’s how to redirect emails received at a zimbra-free address:
Tutorial
1/ in zimbra_free: https://zimbra.free.fr
log in
2/ click on the gear: "preferences"
3/ "client type"
4/ check: "standard HTML"
5/ click on the little blue diskette "save"
which is located just above "connection options"
6/ log out of zimbra at the top right: "log out"
7/ log back in
8/ return to "preferences"
9/ "email filters"
10/ + "new filter"
11/ the rule to create is, for example:
if the sender field does not contain ddddd, then "forward to address" my new email address @ a good email provider.com
12/ "save"
13/ check the presence of the new rule in the list, click on it and verify its wording
14/ send an email to "my-crappy-address @ (zimbra).free.fr"
15/ check that the message has arrived in the inbox of "my new email address @ a good email provider"
---------------------------that's it.
this way all new received messages are forwarded immediately (and do not stay on zimbra-free).

Attention: the retrieval of Free emails works with the incoming mail folder.
Not with the subfolders. Therefore, you need to rebuild the structure of the subfolders or copy them manually.
Personally, I have both accounts on Thunderbird and I dragged and dropped my subfolders to create a copy in Gmail. All done via IMAP.

I'm struggling more to retrieve my contacts from Thunderbird to Gmail, whether directly or via Zimbra (Free). If you have any ideas...

Hello

to sync contacts from Thunderbird with Google or Zimbra, I use the Zindus add-on for TB, which works great.
https://addons.thunderbird.net/fr/thunderbird/addon/zindus/