The 'DotNetNuke.Services.Mail.SendBulkEmail' class was deprecated sometime prior to DNN version 4.9.5 and removed completely around the time of DNN version 5.3.0. It was replaced by DotNetNuke.Services.Mail.SendTokenizedBulkEmail class. The error message is an indication that the Newsletter module being used is a old version, pre-DNN 4.9.5.

Are you launching the Newsletter module in DNN 7 by selecting Admin --> Advanced Settings --> Newsletters in the ControlBar or by browsing to an existing site page on which the Newsletter module had been placed pre-DNN 4.9.5? It may have been called Bulk Mail at that time.

If you are launching the Newsletter module correctly via Admin --> Advanced Settings --> Newsletters in the ControlBar then there were problems with the upgrade. In that case. When the correct version of the Newletter module is opened the browser address bar should show mydomain.com/Admin/Newsletters.aspx. If that is not the case, check the folder admin/Users in the installation's root. Do the files bulkemail.ascx and bulkemail.ascx.vb exist. They should not be present - only ViewProfile.ascx and ViewProfile.ascx.cs and an App_LocalResources folder should be present.

Let us know what you discover and we'll see where to go from there. Hopefully the problem is due only to not launching the correct Newsletter module.

I suspect now that the "newsletter" module that you were using was not the pre-DNN 4.9.5 built in one but rather a third-party module. As I recall the old DNN newsletter module did not support stored subscriber lists (other than selecting the "Subscribers" role in the Send To Roles grid. Nor did it support an unsubscribe link being sent in the email. Perhaps the developer/vender of the "newsletter" module you were using has a DNN 5 or 6 compatible version that would work with DNN 7.

Seeing a "Bulk Email" command and not "Newsletters" in the control bar's Admin --> Advanced Settings menu is rather odd. Was the pre-DNN 4.9.5 page used to access your newsletter module also named "Bulk Email"? When you select "Bulk Email" from the control bar - what url appears in the browser address bar?

Please check the folder DesktopModules/Admin to see if you have a child folder Newsletters and look at the Date Modified of its files (in particular Newsletter.ascx and Newsletter.ascx.cs) - they should be 11/27/2012 or later. Also, check the DesktopModules folder and the Host --> Extensions, Installed Extensions page to see if your old newsletters module still exists somewhere. But, even if it does exist it would not be compatible with DNN 7 due to the error you first reported.