You can install the package with the command below, depending on your os:
$ yum install ulyaoth-smtpping
$ dnf install ulyaoth-smtpping

smtpping

A simple, portable tool for measuring SMTP server delay, delay variation and throughput.

Available Packages:

Package Version
ulyaoth-smtpping 1.1.3

Supported Operating Systems:

Operating Systems Versions
Amazon Linux latest
CentOS 6, 7
Fedora 19, 20, 21, 22, 23, 24, 25
Oracle Linux 6, 7
Red Hat 6, 7
Scientific Linux 6, 7

ulyaoth support