You think you have everything configured to send out a report once your SQL Maintenance Plan is finished. You configured your profile, configured the account and email server correctly, and sent a test message and received it. But did you set the profile to be the default profile?
Open SSMS and double click on Database Mail.
Click Manage profile security.
Click Next.
Click the drop down box under Default Profile and select Yes.
Click Next.
Click Finish.
You now should receive email notifications once the Maintenance Plan is done.