I am very pleased to let you all know that Exchange Server 2007 SP3 is available for download. As we highlighted in Updates to the Exchange Supportability Matrix this past November, this third...
Updated Jul 01, 2019
Version 2.0
Blog Post
1 MIN READ
Ask and you shall receive - Exchange 2007 SP3 w/support for Windows Server 2008 R2 Now Available
Abdul,
Since your environment is E2007 SP1, when you extend the schema you will get the E2010 RTM schema extensions as well as the E2007 SP3 schema extensions (UM changes as well as some additional POP/IMAP security attributes).
The order in which you upgrade your sites should be:
1. External Facing site
2. Internal Facing site
So if the UK site is the site to which you have your users access OWA to get to their mailbox (which may be located in a downlevel site), then yes you want to upgrade it first.
Also remember to upgrade them in the appropriate order, CAS, HT, and then MBX.
Ross
Since your environment is E2007 SP1, when you extend the schema you will get the E2010 RTM schema extensions as well as the E2007 SP3 schema extensions (UM changes as well as some additional POP/IMAP security attributes).
The order in which you upgrade your sites should be:
1. External Facing site
2. Internal Facing site
So if the UK site is the site to which you have your users access OWA to get to their mailbox (which may be located in a downlevel site), then yes you want to upgrade it first.
Also remember to upgrade them in the appropriate order, CAS, HT, and then MBX.
Ross