Yes. You can remove validated email addresses to make sure nobody sends messages to that email address from Bloomerang Volunteer:
If you are in more than one organization, make sure you are in the right one.
Do one of the following:
For an organization-level email address, click Communications from the side menu, and then click Email Configuration.
For an opportunity-specific email address:
Click Opportunities.
Select an opportunity, or use the search box to find and select an opportunity.
In the opportunity menu, click Communications, and then click Email Configuration.
On the Email Configuration page, click the Manage Senders tab.
Hover over the email address, and then click Actions.
Select Remove Email.
On the confirmation page, click Remove.
Bloomerang Volunteer deletes the email address.
To use the deleted email address, you must validate it again.