I have an application that requires an MTA with the following capabilities:
- be able to receive email for multiple addresses in a single domain, e.g. email@example.com, firstname.lastname@example.org, and so on.
- the mails will be received from a single msg service provider, this will not be a public facing MTA
- must support TLS
- should store incoming msgs in the Maildir format (existing legacy application expects each msg as an individual file)
- should be able to check incoming msgs for viruses using clamd
- single catchall mailbox, no pop, imap clients.
The incoming msgs will be processed by a script, scraped for information, then fed into an application for processing and storage. There will never be mail clients connecting to this MTA. In other words, this is really not meant to be an email server in the traditional sense, rather a component of a larger application acting as a means to receive information into the application from one of it's sources. While one might question the rationale of using an MTA for this purpose, that's beyond my scope, it is a legacy application and changing that structure is simply not efficient at this point. The current setup runs on Windows using an old version of Rockliffe Mailsite. I wish to move this function over to Linux for a variety of reasons.
I have looked far and wide, and other than Postfix, haven't really found anything that would serve the purpose. Except that Postfix appears to be an overkill for the intended purpose. Sendmail is too old and Exim doesn't appear to be actively maintained (I could be wrong?).
My primary concern with Postfix is that I might end up opening a can of worms in terms of security maintenance by going with an application as sophisticated as Postfix for a purpose this limited. That said, I am also loathe to try some nameless tool.