How to test Sender Verification with Exim

Introduction

The following technique can be used to see if Exim can verify a sender.

You may also be interested in the following resource for more context:

What is the difference between "Sender Verification" and "Sender Verification Callouts" in the Exim Configuration Manager?

Procedure

1. Login to your cPanel server via SSH or Terminal as the root user

2. Execute the following command with with the email address that would be sending a message to the cPanel server that you are logged into:

exim -bvs sender@remotedomain.tld

If this does not provide enough detail, you may add the -d flag to the command to provide a great deal of extra information:

exim -d -bvs sender@remotedomain.tld

This is documented here:

The Exim Command Line

Here are some key excerpts:

Verification differs from address testing (the -bt option) in that routers that have no_verify set are skipped, and if the address is accepted by a router that has fail_verify set, verification fails. The address is verified as a recipient if -bv is used; to test verification for a sender address, -bvs should be used.

-bvs

This option acts like -bv, but verifies the address as a sender rather than a recipient address. This affects any rewriting and qualification that might happen.