By default Matomo (Piwik) will try to detect the current Hostname and use it in all emails sent. In some cases, the hostname cannot be detected and Matomo will use “”. You can specify your domain name to appear in From: email addresses by adding the following lines in your config/config.ini.php file:

defaultHostnameIfEmpty =

This will affect all emails sent from Matomo: Password reminder, Email reports. You can also change the default email address “From:” in PDF reports emails.

Previous FAQ: Matomo reports this error and fails: “Fatal error: Allowed memory size of X bytes exhausted (tried to allocate X bytes)”. What should I do?