The email address in the panel reaches a person. It is published as text and as a link, deliberately, so you have a record of what you sent and somewhere to attach a photograph or a spool label if that helps.
What is worth writing about
Corrections. A density, a temperature range, a shrinkage figure or a wattage number that does not match the data sheet or your own meter. Include where your figure comes from if you can — a data sheet, a plug-in meter reading, a weighed print — and it will be checked against the source rather than swapped for whichever number arrived most recently.
A calculator result you do not believe. These are the most useful messages. Tell us the inputs you used and the answer you expected, because a disagreement usually points at either an assumption that is not stated clearly enough or one that is genuinely wrong.
A material or printer that should be here and is not. Especially printers: the profile list covers machines people commonly own, and that set changes.
What will not get a useful answer
Diagnosing a specific failed print from a description alone. The troubleshooting section is organised by symptom and explains the mechanism behind each one, which will get you further faster than any reply could.
Response time
This is a small independent site, not a support desk. Corrections are usually acted on quickly because they are cheap to verify; longer questions take longer.
Before you write
If your question is "what should I set X to", check whether it already has a quick answer — those pages exist because the same questions come up repeatedly and a published answer helps everyone rather than one person.