Tag: Qmail

Email is a crucial component of our online lives. Almost everything we do online requires an email address, including creating login credentials, signing up for newsletters, and leaving website comments. There's a good chance you've already encountered spam if you have an email address.

In part one of How to Troubleshoot SMTP Errors, we reviewed email status codes, internal reasons for email issues, and troubleshooting steps to address those issues. In part two of this series, we will examine some of the external reasons for email issues. 

What is SMTP?

The Simple Mail Transfer Protocol (SMTP) is a communication protocol used to transmit email between corresponding email servers. Using an email client like Mac Mail, Outlook, Thunderbird, or web clients like Gmail or Windows Live, SMTP can send messages to an email server. Although SMTP was initially designed as an email transport and delivery system, it later encompassed the email submission protocols that are now in use by both the Post Office Protocol (POP) and the Internet Message Access Protocol (IMAP). The above-noted email clients use these protocols to retrieve email from an email server. When this system fails, it provides the means to identify and resolve SMTP errors.

Introduction

The most effective method to protect a server from sending spam is to prevent it in the first place. In this article, we provide several techniques to use to keep the server from sending out unwanted spam or junk mail. Typically, unwanted, and unsolicited spam email is usually bulk sent out to an indiscriminate list of recipients. Spam is often used for commercial purposes but can be sent out in massive volume by a botnet or a network of infected computers.

What is Thunderbird?

Thunderbird is one of the most widely used open-source email clients in the world. Mozilla originally developed the software in 2004, but the project waned in 2014/15, and Mozilla stated that they would only deliver security and maintenance updates in the future. Until recently, the community maintained the software when a Mozilla Foundation subsidiary, MZLA Technologies Corporation, took over. Today, the improvements in security and stability are very much appreciated, and since version 78, Thunderbird has built-in OpenPGP encryption technology enabled by default. Earlier versions used the available PGP technology, but it needed to be installed as a supplemental plugin. 

Getting Plesk to listen for SMTP connections on an alternate port is not that difficult to do. However, unlike a cPanel environment, configuring Plesk to do so must be done outside the control panel via the command line.