I know this question has been asked on various forums before, and that all the answer were negative, but many of the answers are quite old, and with Azure developing so quickly it seems useful to ask it again.
Can we run a mail server (such as mailenable) on an Azure VM? And if not, why not?
I've seen one posting on the MS forums (here) that suggests the IP of the Azure machine would be blacklisted as a source of spam. Why would this be (as opposed to hosting a mailserver on a dedicated box)?
You can actually host your mailbox on Azure (but you might not want to), the problem you are referring actually has not only to do with Azure but with any hosting provider. When you buy a box or VM it might be that the IP you receive was used by someone else before. If that person would have been a point to send spam from (intentionally or unintentionally) the IP is likely to be black listed. It seems that Azure is having a lot of problems with having their IP's black listed.
So I'd suggest contacting them directly to see if it's still an issue, if it still is, there are many alternatives to Azure.
In addition to the blacklisting issue mentioned above, the best reason not to do this (according to an answer on another forum) is that PTR records are not supported, which pretty much kills the idea of running a mailserver on a VM.
If all you want to do is send email from an Azure instance, you can use SendGrid to send up to 6,000 emails per month for free. There are paid plans that range from $9.95 thru $399.99 that have more advanced features. I have not used SendGrid personally nor am I affiliated with the company in anyway.
I haven't tried azure; however, currently we run mailenable on parallels and it works perfectly. There's a few extra setup steps, and you need to have a router that can provide double nat support (300 dollars from cisco). But it works like a charm. As long as your DNS settings are accurate blacklisting isn't an issue.
