How do I configure mailhelo for Exim?
In "Home » Exim » Configuration Manager" you need to adjust two settings.
The first is "Use the reverse DNS entry for the mail HELO/EHLO if available". This needs to be turned off.
The second is "Reference /etc/mailhelo for custom outgoing SMTP HELO". This needs to be turned on.
Then, use your preferred text editor to create a
/etc/mailhelo file that resembles the following example: