lgtm, I didn't test but the change is simple and straightforward: just adding a new configuration option for a path instead of using a hard-coded value, can't say much about the tests tho better if someone with more deep understanding of the current tests machinery also take a look at it, the use of sleep give me a bad feeling, I didn't check if other tests also do this

I'm slightly conflicted about this PR.

The additional config option looks innocent enough, it's a bit annoying to add new config options for small things which operators are only expected to edit with alternative deployment options, but fine with me if the chef cookbook needs this. I think my preference is saying "please rebase this on top of #853 so we don't have to put this option into the default-generated chatmail.ini, and can just set a default in config.py for everyone who doesn't need to think about this".

But then there is also the LLM-generated tests; you don't understand what they do, I don't understand what they do, they have some sketchy sleep statement in it... If they were in a separate PR, this one would be long approved.

Also, please fix the lint errors :) https://github.com/chatmail/relay/actions/runs/22113484762/job/63915452488?pr=840

thanks. please simplify the PR along the review comments.