WYSIJA POSSIBLE 3rd PARTY CONFLICTS

Your automatic newsletter might be set to send when a post is published on a specific tag, isn’t it? That’s a bug on version 2.7.7. It should be fixed in the next version 2.7.8.

If you want it to work right now, just downgrade to the previous version: https://downloads.www.ads-software.com/plugin/wysija-newsletters.2.7.6.zip