<div>
<div class="content wysiwyg-content">
We have a cpanel vps with root access. (linux)<br />
<br />
Every now and then we get a client saying they cannot send or receive an email from a device.<br />
<br />
What is the best we to begin diagnosing this issue?<br />
<br />
Here is what we currently do.<br />
<br />
1. Make sure their IP address is not blocked by the server.<br />
2. Do a test email from our gmail account.<br />
<br />
Any steps would be appreciated.
</div>
</div>


We have a cpanel vps with root access. (linux)

Every now and then we get a client saying they cannot send or receive an email from a device.

What is the best we to begin diagnosing this issue?

Here is what we currently do.

1. Make sure their IP address is not blocked by the server.
2. Do a test email from our gmail account.

Any steps would be appreciated.

Cpanel and Mail logs

Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.

Email Servers

Linux is a UNIX-like open source operating system with hundreds of distinct distributions, including: Fedora, openSUSE, Ubuntu, Debian, Slackware, Gentoo, CentOS, and Arch Linux. Linux is generally associated with web and database servers, but has become popular in many niche industries and applications.

Linux

The variety of Linux distributions creates myriad issues relating to configuration and operations when computers are networked, not the least of which is the use of various network management applications, some of which are included with specific distributions, while others are standalone applications.