Can't send newsletter from editor

Ghost version: 3.12.0, installed with DO’s Ghost 1-Click App.

I’m trying to send by email (deliver posts to members) when publishing a post. In the post settings, The Email Newsletter test email is working, but when I press publish, with the send by email enabled, the website just kinda freezes? and nothing happens. No error pop-ups or anything. Without send by email enabled, story publishes just fine.

I’ve set up Mailgun API in Labs setting. I’ve changed the config.production.json file to
“mail”: {
“transport”: “SMTP”,
“options”: {
“service”: “Mailgun”,
“host”: “”,
“port”: 587,
“auth”: {
“user”: “xxx”,
“pass”: “xxx”

That json file configuration is for transactional emails (inviting new authors, etc.). To get newsletters working you have to insert the Mailgun domain and API key:


I did put in the mailgun API. and the test email in labs also work. But the problem mentioned persists. Any other way to troubleshoot?

From what you describe it sounds like the Mailgun configuration isn’t quite right, or that the site hasn’t been given enough memory? Are you able to check the logs for any errors?

The server has 2gb of memory, looks like the website is using about 30% of it at idle. Which logs should I check and how?

For Mailgun API key box, I filled in the Private API key I found from API security on mailgun. And Mailgun domain is filled by a subdomain that’s been verified and ready to use listed on Sending - Domains - Name.

Can you try upgrading to 3.12.1? It sounds like you may have been running into a bug that was fixed in that version.