Want To Change Email Systems

I have had enough of email problems that constantly happen on a server. For about three weeks now I have been dealing with email issues that I am going out of my mind. Does anyone have a suggestion as to a email scheme that will work. Here is what I would like to do. Disable Exim COMPLETELY. Either setup a server for email only or find a email solution. Email will be pointed ONLY by way of DNS.Once I get email fixed on this box it works for a day and next thing you know it's all messed up again. Somehow etc/localdomains and etc/remotedomains either vanish or get over written plus a bunch of other things including permissions.All I know is this is getting ridiculous.I don't want any sort of email system on this box. I want all my email to go though DNS only to another server. We already have on service that we use for Exchange, so all the MX Records point to that server, but email still has to interact with this server first, which I don't want it to.