If allowed by your organization, you can send email to a Teams channel. Teams uses the email to start a new conversation and this is a great way to get a debate going about something which first appears in email. Managing the Teams email integration features isn't hard. You can define domains to accept email from and enable or disable the feature. After that, it's up to team members to use the capability. Hopefully, they'll resist the temptation to remove email addresses from channels, which is something which should be limited to team owners.