I can't imagine that Breeze was all that resource intensive to maintain, but I don't really know what goes into such a service.
As far as I understand it, they send the e-mail directly from their own servers. Maintaining a system to do this reliably is quite labor intensive as you need to try and get (and stay!) whitelisted with the larger providers and constantly put out 'abuse' fires. Dealing with e-mail is a labor intensive pain in the ass at the best of times..
As far as I understand it, they send the e-mail directly from their own servers. Maintaining a system to do this reliably is quite labor intensive as you need to try and get (and stay!) whitelisted with the larger providers and constantly put out 'abuse' fires. Dealing with e-mail is a labor intensive pain in the ass at the best of times..