Exchange Failover Single Server

[RocketTech]

I have an Exchange Server 2010, self-hosted. I have 2 ISPs, both with static IPs. I currently Use a static IP from ISP 'C' for mx and ActiveSync. I would like to use a static IP from ISP 'E' for redundancy. Redundancy for receiving e-mail is critical, any other consideration is secondary. In a Server 2k8r2 Exchange2010 environment, is this possible with a single box, or do I need a separate edge server? I don't think I have enough horsepower to run a VM, unless the load would be very light.
I use pfSense, if that becomes a consideration.

 

[Biznatch]

Can't you just add the second IP as another MX entry in your DNS? Then add the second static IP on the network adapter so it listens for incoming SMTP traffic from both IPs.

 

[RocketTech]

Can't you just add the second IP as another MX entry in your DNS? Then add the second static IP on the network adapter so it listens for incoming SMTP traffic from both IPs.

That's what I'm hoping for, just making sure that is the case before mucking about.

 

[hutchingsp]

Just setup a couple of MX records on both IP's with the relevant priorities and do whatever you need to do with your router(s) to get both forwarded to your Exchange box, job done.

Depending if you want one connection to take priority over the other you may want to setup a different A record for each MX record to use to bounce mail to the correct ISP.

If you really want redundancy I'd suggest look at an offsite secondary MX as nothing you do will matter if your mail server goes offline or you have a power cut etc. Though I wouldn't worry too much as email is, by design, store and forward and should retry.

 

[kbrennan]

+1 on hutchingsp's post. Unless you're ISPs are totally unreliable, your bigger chance of downtime and data loss is the single point of failure known as the server.

 

[RocketTech]

I have mailbagging setup, working, BUT have no control over when the mailbag forwards to the server. Least reliable point is the ISP.
I want to minimize delay of mail delivery when one ISP goes down, as the customer is on tight deadlines and can lose money with delayed e-mail.
In a perfect world I would have two mail servers, but the budget does not allow it and there are <20 users.

All-in-all, reliability is acceptable except for ISPs- at least when one is down, the other is usually up.
You did remind me that Office365 offers MX redundancy, IIRC. Anyone have experience with that?