Unable to setup a functional SMTP account with local cloudron mailbox

[overclockmp]

Hello everyone,

I am currently trying to setup a send email node in n8n.
I have done what was suggested here and I created a specific user for this. I have also setup a mailbox associated to that user.

Outbound emails work fine already with any apps (relay through mailjet).
I have added the new user email as a sender in mailjet config.

I have used the credentials from that new user to setup the n8n SMTP account.
I use port 587 and mail.<domain> as the host.
SSL is disabled and STARTTLS is enabled.

I have also added the client host name as the n8n hostname.

Is there a better way to do this now? (this linked post is from 2021, so maybe this information is outdated).
Is there something I missed?

Thank you all for your help