[264] An attempt was made to send an email when no email session has been established

The following error message found in the SQL Agent logs:

Message: [264] An attempt was made to send an email when no email session has been established

This is known issue and workaround provided as below:

• right-click on SQL Server Agent and select "Properties."
• Click "Alert System"
• Unclick "Enable mail profile"
• Right-click SQL Server Agent again and select "Properties."
• Click "Alert System"
• Re-click "Enable mail profile"
• Click "OK"

After performing the above actions.. to take affect please restart the SQL Agent:
• Restart SQL Server Agent

Please let us know your comments…

Thanks,
Satish Kumar.