When you say it only happens in dev is that a dev environment of n8n split from your prod or is it a different workflow? The error itself just looks like a fairly generic networking issue and not really an issue with n8n itself but maybe the configuration or the network.
Is it on the same host machine or is it a different physical box? That error sadly is a networking issue so this will be a case of working out what is different.
Perfect, So I would start by looking at the routing or the machine settings. There is not really anything we are able to do at this point as the issue appears to be outside of n8n.
Hey @Jon
We also use Talend from the same machine, and from Talend, we can send emails using Mailjet. That’s why it makes us think of an issue with n8n.
Sadly just based on your screenshot it looks like a generic netork / routing issue. This could be a docker setting or something else, I would say as your prod n8n instance works that would rule out a general bug in n8n and points more towards the environment.
Are you running n8n in Docker or on the machine itself?