Gmail is not a good match to Odoo since it doesn't permit sending emails on behalf of different users (even of the same domain). Particularly, you have to authenticate as tom@yourdomain to send as Tom, but not the way Odoo wants it to be handled when all the emails got sent via a shared email address such as system@yourdomain or catchall@

Please be informed that there's one more issue related to that.

https://www.odoo.com/forum/help-1/question/how-do-i-configure-the-catchall-address-to-properly-receive-replies-on-odoo-sh-136322

Indeed, this is crazy that such a basic feature as email delivery doesn't work reliably, but it's true.

As for a workaround, I came across an OCA module that sends a rejection notice to the sender, but that's not what we want at all! I mean bothering clients with this fluff is a bit dull, isn't it?

So I'm just going to make that OCA module forward those messages to our own predefined email address instead..

If you need such a fix too, please just drop me a line at vi3ual[at]gmail.[соm] and I'll just send you a modified module free of any charge.

Regards, 

Arsenty

You will need to login to your G Suite (Google Apps) admin console to create this catch all account, you should either be a G Suite super admin or delegated admin to complete this task.

I have a step by step video that might help.

https://www.goldyarora.com/creating-catch-all-account-which-works-with-multiple-domains-in-google-apps/

Thanks for the reply. I tried to edit the title but keep getting 404 error.

As for th eissue at hand, the Google documentation didn't help. The first section says "This feature is only available with the legacy free edition of Google Apps" and second section "Set up catch-all routing with the Routing setting" directs to domain-level page that says "The Email routing setting is deprecated and will soon be removed from usage, replaced by the Routing setting"

So loop-de-loop.

I still don't understand the function of the catchall address. The Google documentatins says:

Designate a catch-all address only when you really need it. Spammers often try to guess email addresses in your domain. When they guess incorrectly, the spam is delivered to the catch-all address. The volume of incoming messages can exceed the Gmail receiving limits, resulting in the account becoming locked. Or, it might lead to legitimate messages being deferred, delayed, or bounced.

How does Odoo implement the address function?

The proper title of your question should be: "How to setup a catchall address with GMail?". A catchall email address is not the literally "catchall@mydomain.com", but something like "*@mydomain.com", means everything before @mydomain.com will be routed to the email address catchall@mydomain.com. You may read this on how to setup a Gmail catchall address: https://support.google.com/a/answer/33962?hl=en