I have two sites that have RVS4000 Routers. Both of these sites contain Canon Imageclass MF5950dn printers. One of the capabilities of this printer is to directly e-mail scanned documents to a recipient. The e-mail server is hosted by a 3rd party. Both sites will not allow the printer to e-mail scanned documents. the RVS4000 is the only common element. At one site, I swapped the RVS4000 with an RV042 and the printer would e-mail scanned documents flawlessly. But, the RV042 would consistently drop its tunnels to my other sites. When I put the RVS4000 back into production, the tunnels were stable, but the printer would no longer e-mail. All devices have the most updated firmware (as of today 5/23/2014). The canon diagnostics leave a lot to be desired. All I get is a TX Result Report that says "error". The smtp server does not require authentication. I have these printers at other sites and their e-mail functionality works fine, but the other sites do not have RVS4000 routers. Any help or suggestions with this issue would be greatly appreciated.