Add custom header to proxy requests for Postal E-Mail Tracking

[drtech981]

I am trying to add a custom header X-Postal-Track-Host for click based email tracking as mentioned in here

Here's my custom config for the proxy host :

However, click based tracking fails, and the destination webpage is showing a 404 error (indicative of that the header was never sent to the upstream host for the proxy server).

How do I set a header to sent upstream correctly ?

[chaptergy]

Unfortunately nginx has this quirk that if any headers are set in a location block, the headers from the server block are ignored. And there are headers in the default location block. So you would have to overwrite the custom location / and add the header there instead of in the advanced config.