Renewing Self Signed Certificate in SBS 2008

When I originally set up our SBS server I set our domain to what I will call ABC.com. After some time the owners wanted a different domain for email. To do this, I went into the exchange server Organization\Hub Transport and set up a new Accepted domain of  what I will call XYZ.com. I then went in to the E-Mail Address Polices and modified the "Windows SBS Email Address Policy" to reflect the new domain. So now when I run the add new user wizard from the SBS Console, the default smtp email address of the new user properly reflects the new domain. This allowed me to keep the ABC accepted domain and continue to receive emails sent to that domain. It also allowed me to not have to change the external domain name, which I was concerned might jack up a whole lot of other things as well. All good.

Two years ago, I had to renew the Self Signed Certificate. I honestly cant remember whether I ran the "Fix My Network " wizard or the "Set Up Your Internet Address" wizard. I think it might have been "Fix My Network". My understanding is that you can (and must) run either of these wizards to renew the cert.

But what I do remember is that the wizard reset (actually overwrote) everyone's default email address back to the ABC domain. The only way I could correct the problem was to go into each and everyone's Mailbox and change their smtp addresses back to the new domain.

It is getting close to the timeframe where I need to renew this certificate again and I really would like to avoid the problem this time around. Has anybody seen this and if so, know how to avoid it?