cURL issue 28: Connection timeout
If you see this error message displayed in your WordPress admin, it means something is preventing your emails to be sent. You may notice the sending is paused or the automated newsletters are not being sent.
cURL error 28: Connection timed out after X milliseconds.
or
cURL error 28: Operation timed out after X milliseconds with 0 out of 0 bytes received.
This is a common issue and it’s not tied to any plugin or WordPress itself. It’s something directly related to a server component, the cURL library, and it affects any web software using cURL.
Here's what you can do and check in order to fix it:
Wise Builds cURL Options plugin
You can install this plugin, which allows configuration and testing of cURL connection options for individual services.
Then go to WordPress dashboard > Settings > cURL Options and click on the "Add Rule" button twice to create two rules:
| Host | Protocol | Option | Value | |
| your website's URL (i.e.: mailpoet.com) | https | CURLOPT_TIMEOUT | 20 or 30 | |
| bridge.mailpoet.com | https | CURLOPT_TIMEOUT | 20 or 30 |
After you've done it, check if the message is gone and sending has been resumed.
Contact your hosting company
If using the plugin doesn't fix the issue, we recommend contacting your hosting company and ask their support team to check the following points :
- Make sure your server is running a recent version of PHP and the cURL library;
- Try to increase your Server Memory Limits settings;
- Ask your host if there is some limitation with wp-cron, or if loopback is disabled;
- Ask your host if there a firewall, CDN, or security modules (e.g. mod_security) that could block the outgoing cURL requests.