You'll also need permanent IPs.
Watch the pricing though, hosting any mail server on a pay-as-you-go cloud host can quickly get more expensive than a more traditional colocation over the five-year life of a typical server.
And even cloud providers have outages...
Hope that helps,
Mark
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___________________________________ L. Mark Stone, CIO "Uptime. All the time."
477 Congress Street | Portland, ME 04101-3431 | (207) 772-5678
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