In Mail Security for Exchange(SMSMSE), cannot see more than 1000 entries under Quarantine.
Working as design.
By default, we can see only 1000 entries under Quarantine.
To increase more than 1000 value we observe console get slow, hence defined to 1000.
We can increase more than 1000 value by changing the below registry.
1. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\SMSMSE\7.10\Server\Components\Quarantine
2. Look for 'QuarantineDisplayLimitDword ' Change the value from 1000 to 1500 value
3. Restart the SMSMSE services.
Note: if you have more than 1000 items in 'Quarantine' folder then only you can see. Location: \Program Files\Symantec\SMSMSE\<version>\Server\Quarantine