> I run exim-4.86.2-3.10.1.x86_64 on my outbound server and for a few
> email address, email sent to them is not delivered.
>
> Error in the server logs is "Too many "Received" headers - suspected
> mail loop"
If there is no mail loop happening, how many Received headers is
considered too many is controlled by the 'received_headers_max' Exim
main configuration variable. According to the current documentation, its
default value is 30. Raising it to some suitable higher value would avoid
the problem.
- cks