Simple Mail Transfer Protocol (SMTP) is a set of rules used while sending emails. Usually, this protocol is associated with IMAP or POP3. However, SMTP is utilized to deliver messages, while POP3 and IMAP are utilized to receive them.

The SMTP testing tool identifies issues with email security in your server that can hinder your email delivery. It checks the health status of your outgoing email server and notifies you about the detected problems, such as connectivity issues, and how to tackle them. An SMTP test tool can identify SMTP server issues and troubleshoot them to keep your email secure and safe.

The SSL Checker tool can verify that the SSL Certificate on your web server is properly installed and trusted.

Cloudflare, Inc. is an American company that provides content delivery network services, cloud cybersecurity, DDoS mitigation, and ICANN-accredited domain registration services.

Registration of international domains can be done through NIC.UA website.

Mailtrap.io is Email Delivery Platform for individuals and businesses to test, send and control email infrastructure in one place.

Infinityfree.com provide free website hosting with PHP and MySQL and no Ads in your website.

The book consists from the following sections:
1. Types of DNS Records.
2. SSL and TLS Certificates:
3. Replacing the Default FortiMail Certificate:
4. Header Analysis:
5. Some Tools for Email Verification.
6. Evaluation of Some SMPT Testing Tools.
7. Microsoft Remote Connectivity Analyzer.
8. Creating Free Domain in nic.ua and Linking it to Cloudflare.com.
9. Mailtrap.io Email Delivery Platform.
10. Sending Emails Using Windows Power Shell.
11. Free Web Hosting from infinityfree.com.
12. Installing Different Types of Plugins Related to Mail on the WordPress Website.
13. Setting Up a Business Email and Email Forwarding Through Improvmx.com.
14. SSL Certificates Checkers.
15. References.