Assuming there are no issues on your web server configuration and the remote server is online, you may want to check if the SSL Certificate associated with the external entity is valid.
When you try to send an email, this error usually occurs because the email address does not exist in the remote server.
You sent an email, and it was bounced (returned) back to you.
Check the error log file for errors. Coding errors on your website are most likely causing the blank pages.
Use the following settings to read and send email messages in mail clients, like Microsoft Outlook and Apple Mail.
As a reseller, most errors in DirectAdmin's File Manager occur when you open File Explorer as a specific user, switch users in another browser tab and go back to the File Explorer tab to make any changes.
Before anything else, make sure the services are working on the specified IP addresses and ports by accessing the services directly.
Check the error log file for errors. Coding errors on your website are most likely causing the blank pages.
If you can use the control panel to manage your service or connect via SSH, it may not be a DDoS attack.
There are different reasons why you might want to convert your certificates to other formats, such as your server not approving a specific format or that format not being compatible with the software or web application you use.
