I have version 7.4 and things are not syncing
NOTE: Add2Exchange Standard edition was retired in 2016. Contact us for your crossgrade options.

The most common reason is the Add2Exchange service is not started, or it is and the Add2Exchange Console is open. Close the A2E Console and restart the service.

Moving along, GET THE LATEST if you have software assurance in place. This is the free stuff if you have software assurance in place, you get newer versions for free

http://support.diditbetter.com/kb/A2E_194.aspx

then do this
http://support.diditbetter.com/kb/A2E_183.aspx

These are always helpful to get a pulse of the system, but be careful in here,
run all diags and that’s about it – look for RED
ftp://ftp.diditbetter.com/A2EDiags/A2EDiags.exe

Make sure your relationships are set correctly.  Open the Add2Exchange Console
http://guides.diditbetter.com/a2e-guide/initiating_the_upgrade.htm

Incidentally,  we can recertify your machine and help you with all of this
if you are on Premier Support - open a ticket online. One of us will log in remotely (without requiring any credentials) to help you. 

• Professional Services Support Options | Premier Support overview: https://www.diditbetter.com/premier-support
• Preparing for a remote session: https://www.diditbetter.com/remote-support

If you wish, reply to all and we will send you a formal quote for a single remote session $199 Buy Now

But most choose a block of Premier Support 4 hour for $399  Buy Now and this would take an hour to recertify your machine and any time remaining after the session can be used for any future remote/phone support requests. With Premier Support, other benefits offer you a 50% savings on the tools -- the Recovery and Migration Manager is only $125 (reg. $250)  Buy Now

as is the ToolKit (only $125 - reg. $250) for migrations, moves and startovers   Buy Now
 

If you do all this, and it works, let us know if this fixes you.