Maybe we rename the post, how to avoid getting labeled a ruthless spammer? 2 lists - 52000 who have opted to receive communications and 38000 who signed on before the opt-in was devised. I checked with the webhosting provider. They are suggesting an Ultra conservative approach: Q2) 52000 emails on a level3 VPS... well, I'll tell you what, 52000 emails is a lot on any machine. The only way to send out that amount of emails in a relatively short span of time would be to do it from a whole bunch of different email addresses. We could set up a cron job to tell exim (your mailserver software) to change IP address every hour, and go from there. Then we'd just have to worry about the capacity of the VPS. In order to not get banned, you'd want to send out no more than 500 emails per hour (or 8.333 per minute, which your VPS should be able to handle). ...So if we round things a bit to be on the safe side and go with 7 per minute, you get 420 per hour and 10080 in a day, so it'll take a little over 5 days to send them all. Also, if you can do it, it would be great to spreeeeeeeead out email addresses that are going to the same ISP (you know, @comcast.com, @att.com, @yahoo.com, @gmail.com --- the more mixed up, the better). ----------------------------------------- --> Okay so say this is doable. I can't imagine that Twitter, or FaceBook or even list mailing service is constrained to go to this length to avoid getting blacklisted. They must have something in their back pocket - technical agreements with major providers, etc?