Installed Package Limits may be the reason; you may need to upgrade Editions.
Salesforce.com limits the number of third party and Salesforce.com “packages”or applications that can be used with its cloud service. The package or AppExchange limits are based on Salesforce.com Editions.
|Edition||Price per Month||# of Apps|
Contact Manager does not allow the user to use an external application from the AppExchange with Salesforce.com. Group Edition users encounter these limits quite often, because the Group Edition only permits the installation of one app or third-party package. The Professional Edition may install 5 apps or packages; the Enterprise Edition may install 10 packages or AppExchange apps. If a Group Edition user has downloaded just one application from the AppExchange, they run into hard limits and must upgrade to the more expensive Professional Edition. Interestingly, it is easy to upgrade a Salesforce.com account, but very difficult to downgrade.
Most often Match My Email support encounters the package or application limit during setups for Group Edition users. To check the numbers of Salesforce.com applications installed follow these steps (click images to maximize):
If you any questions about the resources – Data Storage, File Storage, API Calls, # of Packages Installed –that Salesforce.com allocates to the various Editions, please contact Match My Email at firstname.lastname@example.org.