Integrating intranet web logins with AD emails For various reasons, one of our corporate intranet sites in development cannot use Active Directory groups or passwords. Users logins will be stored within a MSSQL database instead.

However, we do want the ability to send email notifications to these users using their AD registered email address. All users will exist in AD.

So my general question is what is the better approach:


Use SQL to query the AD for emails when the web application wants to notify selected user(s)
Store the email addresses in the MSSQL database and update records via a batch process each night?


The first seems to have less duplication, but performance could be slower (and vice-versa). Is there another method?

Edit

To answer your questions, the emails will generally be initiated by other users. For instance, after modifying a document the editor will have the option to send a notification to be sent immediately. The plan was to have the ASP.NET application handle sending mail. In terms of volume, peak usage would be around 200-300 a day.
It would appear that the responsibility of sending the email lies with the ASP.NET application not the database.

I would perform a lookup of the users email from AD within the ASP.NET application and generate the email that way.