Send transactional email

We now get emails in services like quotefault, implement sending emails to people when they're:

1. Marked as absent from house meeting
2. Have met a requirement (reached the 30 meeting requirement)

Start by locating the code that marks someone absent from a house meeting and the code that checks the 30-meeting requirement. Review how quotefault sends email, as referenced in the issue, and determine the project’s existing notification and recipient conventions. Done means both events trigger transactional emails to the affected people.

Written by the indexing model from the issue text.