Yes, of course! We are constantly testing with the latest versions of popular add-ins. The record holder email2 users is currently 33 concurrent add-ins in Outlook.
If you do find an Outlook add-in that appears to be conflicting with the proper functioning of email2, do not hesitate to contact us using the 'Report a bug' feature under the 'Tools' menu of the email2 Toolbar for Outlook.
//Edited June 2009