For the UK, ICO: https://ico.org.uk/media/report-a-concern/forms/1479/spam-email-or-fax-concerns-form.pdf https://ico.org.uk/media/report-a-concern/forms/1479/s

For the UK, ICO: https://ico.org.uk/media/report-a-concern/forms/1479/spam-email-or-fax-concerns-form.pdf https://ico.org.uk/media/report-a-concern/forms/1479/spam-em... They ask to send them the spam emails (with headers) to them, all communication from and to. I guess it's the same around the EU, just the relevant national agency.