Hello,

It looked like mails are already release. But in your case you said that clients couldn't get the mails released from Quarantine. You can change Administration/Control Center/SMTP/ and fill the "Define New Host" settings to send mails like notifications,quarantine release mails etc. from another SMPT like your Exchange server. 

You need to give relay permissions in your SMTP also to accept connections from SMG.

Regards,

Oykun

Why we need to create new host and all before upgrade it is working fine only..

Hello,

There are also other solutions available as you can see in the document below ;

http://www.symantec.com/business/support/index?page=content&id=TECH89134

However the most easier one is 3rd choice i think :)

Regards,

Oykun

Hi,
You do not receive external emails?
It was the same after the incident is locked?
The spam emails with were quarantined and evaluated?
After the vaccine, they are still infected?
The SMTP is directed to another port other than the default?
Was modified to port direction?
Ensure that only external emails from the spam classification is not received.
Attempts to answer these questions paa I can help you!

hugs