support multiple email recipients

[kumarabhishekpandey]

Support multiple email recipients

Description

In current version of SE, email recipient get_to_mail is expected to be a single email address.
The change ensures that if get_to_mail contains multiple email addresses separated by commas, they are split into a list of individual email addresses before being passed to the sendmail function. This is necessary because sendmail expects a list of recipient addresses.

Related Issue

112

Motivation and Context

How Has This Been Tested?

Uploaded wheel file generated to Databricks cluster ran spark expectations job.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[asingamaneni]

LGTM