This might help? http://technet.microsoft.com/en-us/library/dd335108.aspx
2010/1/13 Ellis, John P. <johnel...@wirral.gov.uk> > Is there such thing as an Exchange 2010 sizing guide? Currently we are > using Exchange 2003 and im trying to size the servers > Currently we have about 4300 users and this will probably grow to 5500. > > Thanks > John > > ********************************************************************** > This email and any files transmitted with it are confidential and > intended solely for the use of the individual or entity to whom they > are addressed. If you have received this email in error please notify > the system manager. > > This footnote also confirms that this email message has been swept by > MIMEsweeper for the presence of computer viruses. > > www.clearswift.com > ********************************************************************** > > > > > -- Regards, Clayton clay...@alsipius.com http://alsipius.com