[brianwawok]

I don't know how SES works. Some of the other providers lump groups of users together. If you get in a group with spammers, your sending server gets tarnished. You can usually email support and get moved to a different group.

Not sure if SES offers this. The other guys will. That alone could be reason to try it out? Shouldn't be hard to with gateways for 1 blast and see how it performs.

[jlgaddis]

Indeed, I see connection attempts everyday from mail servers on SES, Mailchimp, Sendgrid, etc., that are blacklisted. That mail will never get delivered to my customers, even if it's 100% legitimately non-spam.