Article PS040225132 AspEmail errors under ASP.NET Problem Description When using AspEmail under ASP.NET , one of the following errors occurs: An Error Occured: System.NullReferenceException: Object reference not set to an instance of an object. Compiler Error Message: CS1501: No overload for method 'Send' takes '1' arguments Solution The most likely cause of these errors is that your web application has a version mismatch, between the AspEmail core file AspEmail.dll , and the AspEmailLib.dll wrapper library for .NET. Make sure you've downloaded and installed the newest version of AspEmail. Find the AspEmailLib.dll file included with that (usually installed in the folder C:\Program Files\Persits Software\AspEmail\Samples\Bin ) and copy it to the \Bin folder of your web application. Created: 2/25/2004 5:00:02 PM Last Modified: 11/14/2005 11:05:47 AM Copyright © Persits Software, Inc. 1998 - 2019 For technical support, write to support@persits.com.