After configuring SQL Server database mail and testing it successfully, you could find maintenance plans unable to send e-mails although you have set the recipients correctly.

This is generally due to the setting for the default profile for database mail.

Generally, you need to do the following to configure database mail:

1.       In SQL Server Management Studio, select Management, Database Mail

2.       Select Configure Database Mail

3.       On the Database Mail Configuration Wizard, select setup Database Mail and configure the SMTP settings

Secondly, you need to configure the default profile as follows:

1.       In SQL Server Management Studio, select Management, Database Mail

2.       Select Configure Database Mail

3.       On the Database Mail Configuration Wizard, select Manage Profile Security

4.       Under Public Profiles,  select Yes in the Default Profile to set the default Profile