The page piwik.org/contribute/ has an item:
Security review
If you like to delve into code to look for security issues, please do so, and submit us any problem you can find or suggestion on how to make Piwik more secure.
with a link to mailto:hello@piwik.org
When I send an e-mail with that address, I get a message from Mail Delivery Sytem [MAILER-DAEMON@piwik.org)
with conflicting information. The subject implies that the e-mail was not delivered by the content states that it was delivered. I’m not sure whether it got through or not.
For security reasons, of course, I will not respond to e-mails sent directly to me in response to this message, only to forum posts.
Hope this helps,
Charles Belov
SFMTA Webmaster
www.sfmta.com/webmaster
Subject: DELIVERY FAILURE:
Content:
This is the mail system at host piwik.org.
Your message was successfully delivered to the destination(s) listed below. If the message was delivered to mailbox you will receive no further notifications. Otherwise you may still receive notifications of mail delivery errors from other systems.
The mail system
hello@piwik.org: delivery via local: alias expanded