Jerry has a good point here. Consideration should be given to setting up separate Users instead of identities. I use a combination of them depending an who I wish to appear to be. At the office I have Pegasus set up as two users, one to administer the general mailbox and on for my personal mailbox. The "General" user has around 12 identities (accounting, sales, PMail support, Mercury support, CFO, etc.). I use filters to direct mail to different folders on which I have default identities set. As has been mentioned, the challenge with identities is insuring that you use the correct identity when sending or replying. Also, with identities you work with them all in the same instance of Pegasus whereas with Users you access each in its own instance of Pegasus.
Jerry has a good point here.  Consideration should be given to setting up separate Users instead of identities.  I use a combination of them depending an who I wish to appear to be.  At the office I have Pegasus set up as two users, one to administer the general mailbox and on for my personal mailbox.  The "General" user has around 12 identities (accounting, sales, PMail support, Mercury support, CFO, etc.).  I use filters to direct mail to different folders on which I have default identities set.  As has been mentioned, the challenge with identities is insuring that you use the correct identity when sending or replying.  Also, with identities you work with them all in the same instance of Pegasus whereas with Users you access each in its own instance of Pegasus.