An error occurred while sending 'HTML Email Report

Error was ‘Could not open socket’ when sending a report. How to manage this?*


This error message comes from the connection between PHP and your mail server. Have you enabled SMTP in the E-Mail settings? If yes, check the settings there, if not check your PHP mail() config.

Which settings in WHM should be set inside PHP mail() config

We have tested and seen an issue as CPanel should be set as SMTP restrictions DISABLED. This blocks and Matomo SMTP connections.
Maybe it is better to add also SSL/TLS not only SSL or TLS and missing also field for the port 25.