I found a couple things that is leading me to believe that this may not be a simple config change.

port here with no answer
http://communities.vmware.com/message/1130892#1130892

Found some VC1.1 Documentation that seems to have the ability to change the port much easier
http://www.vmware.com/support/vc11/doc/c15alarms.html

I have attached the pic from VC 1.1 that you can edit the server port and a screen shot of what I think is the only config page for VC 2.5

Any help would be great. Thanks guys

Hi Dave. I did a bit of digging around and it looks like the port # for SMTP is in the VC database itself. The "name" value in the database is mail.smtp.port, so based on your other links I'd say that you should be able to change the port by going into Administration, VirtualCenter Management Server Configuration, Advanced Settings, then entering a key of "mail.smtp.port" and a value of whatever you want it to be set to. You'd then need to reboot the VC server (or at least restart the VC service) to get the changes to take effect.

You can verify that the change "stuck" by looking at the vpxd.cfg file (on the VC server under Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter). That's an XML format file so you'll see the entry as a series of "nested" entries rather than as "mail.smtp.port". Note that the change does NOT appear in the VC UI, so you won't see anything if you go back to Administration, VirtualCenter Management Server Configuration, Advanced Settings again.

According to the docs I read the entries in the vpxd.cfg file will override whatever is in the database, so that should work. If it doesn't then you can try the unsupported way by changing the database itself. Beware that this is completely unsupported, and while I don't see any reason that it should break anything, it may hopelessly screw up your VC database forcing you to restore from backup or re-install. The change may also be "undone" by doing something like changing the SMTP server name at a later date from the VI client. Proceed at your own risk .

1. Download a copy of MS SQL Server Management Studio Express (a.k.a. SSMSE) (http://www.microsoft.com/downloads/details.aspx?FamilyId=C243A5AE-4BD1-4E3D-94B8-5A0F62BF7796&displaylang=en)
2. Install SSMSE on your VC box
3. Start SSMSE and connect to the VC database instance. If you've installed SQL Express on the VC server itself the server and instance will be automatically populated (i.e. VCServerName\SQLEXP_VIM), otherwise enter the database server housing the VC database and Connect
4. Open Databases, VIM_VCDB, Tables then right-click on dbo.VPX_PARAMETER and pick "Open Table". In the NAME column go down to mail.smtp.port and then change the VALUE column to be the port number you want.
5. Click on another row to save the value (you'll see the little "Pencil" in front of the mail.smtp.port row disappear)
6. Close SSMSE
7. Reboot the VC server

Hope one of these work for you...