You probably only have the default Maven repositories and none that can solve this dependency.
Like simple-email is not in the repositories that are standards you should add a repository that solves such a dependency.
Apparently such library is not in a public repository, at least not found, if you find such dependency in some public repository, you can include in your pom.xml, something like this:
<repositories>
    <repository>
        <id>simple-email-repo</id>
        <url>http://urldorepositorio.com/repo</url>
    </repository>
</repositories>
Or include in your settings.xml, one way is this:
<profiles>
    <profile>
        <id>simple-email</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <repositories>
            <repository>
                <id>simple-email-repo</id>
                <url>http://urldorepositorio.com/repo</url>
            </repository>
        </repositories>
    </profile>
</profiles>
So the simplest way to solve it is:
- [You will need to use git in this step] Clone the library repository: git clone https://github.com/codylerum/simple-email.git
- Walk to the folder where the clone was made: cd simple-email
- [You will need to have the Maven configured correctly in your OS] Install the library to your local Maven repository: mvn install -DskipTests=true(the tests are failing, so we won’t run them)
- Once successfully installed, update the dependency on your pom.xmlfor the version0.2.1, which is the current version of the project that has been cloned, thus:
<dependency>
    <groupId>com.outjected</groupId>
    <artifactId>simple-email</artifactId>
    <version>0.2.1</version>
</dependency>
P.S. 1: if your project does not already have dependency on simple-mail, you may consider using some other library that is in the Maven central repository, such as Simple Java Mail, Apache Common Email, etc..
P.S. 2: another way of solving is to include the project of which simple-email is Fork, the Seam Mail, if it is convenient for your case.
							
							
						 
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– Victor Stafusa