How to resend a quarantined mail from the local quarantine?

There is no GUI possibility to achieve this. The easiest possibility to handle the quarantine is to configure a local email address as quarantine destination. So you can archive it within an IMAP folder on your Mail server and handle it as normal Mail with a normal Mail client.

However, if you read this you probably chose to have the quarantine locally on the Firewall, which is also the default.

In order to get your mail, log in to the firewall using SSH and do the following:

1. Search the desired quarantined message. The messages are archived within /var/amavis/virusmails/. Spam messages begin with spam-, while virus messages begin with virus- and will be followed by the quarantine ID, for example Q1oQs5iAYKr.
   You can use
   
   ls -l /var/amavis/virusmails/
   
   in order to list the quarantine and for example
   
   zcat /var/amavis/virusmails/spam-0Q1oQs5iAYKr.gz | less
   
   in order to read the specific message.
   
2. Unzip the desired message:
   
   gunzip /var/amavis/virusmails/spam-0Q1oQs5iAYKr.gz
   
   The file will now be named spam-0Q1o!s5iAYKr
   
3. Transfer the file to your workstation using scp or Winscp.
   
   
4. Open the file with your Mailclient.
   
5. Now you can handle it like a saved Mail and forward it to the revipient or extract parts.