I will be setting up some email campaigns for several companies and would like some advice on the configuration -- VPS or dedicated.
That is, each company must have it's own IP address so as to not influence the sender reputation of the other companies. They will all access the same front-end control panel but can identify within their individual accounts which smpt server to use (and they will only be allowed to use their own).
My question is should I go with something like Slicehost which will allow me to set up individual smpt servers for about $40/month (but limited to 256 ram) or am I better off spending the bucks and buying my own high-performance blade server, sending it to a data center/colocator, cutting it up into separate VPS and doing it that way?
With the separate VPS I believe I can get a lot of ram say up to 4 Gigs which would translate into about 10 accounts in my calculations.
What is the anticipated volume of mails? Are you capable of handling the extra complexity of running a bunch of different VPSs to perform SMTP? Will you be able to get enough IPs from a provider to perform this type of setup?
If your intention is to be providing this type of service through a control panel you own and manage would a VPS managed by a third party company even be a viable option? That said I have used Linode before for VPS services with great success. I think I would personally lean toward a good quality VPS provider and a VPS sized to match on an underlying infrastructure that is more redundant than a single server.
The anticipated volume would be about 20,000 - 50,000 per month per account with about 10 accounts anticipated per VPS. As far as IP's are concerned maybe you can answer that for me or someone else can step in and comment -- I've always been under the assumption that if you needed them you can get them, albeit you would have to pay for them. It seems to me that an smtp server is a legitimate reason, but I could be wrong.
I don't need to provide a CPanel-like interface to anyone, as the users would only be accessing their email campaign software which basically just runs on apache. I could do the configuration either command line or if there is a CPanel-ish type of interface (WebMin?) I could use that.
How does one go about allocating the external IPs to individual smtp servers on the VPS? I know that it is possible to create virtual ethernet interfaces per NIC card, but how do you route the external IPs to the internal virtually-nic'd lan ips? Is some kind of software running on the WAN facing side of the NIC that routes the IP addresses to the internal network virtually NIC'd cards?