All blocked E-Mails generate a report saying that the mail has been quarantined. The entire E-Mail is placed under subfolders located at:
/var/lib/amavis/virusmails/
The subfolders are created following the first letter of the quarantine header X-Quarantine-ID. For instance, given a quarantine ID of jBRiR2sOcpbz, the mail will be then stored under /var/lib/amavis/virusmails/j.
After consulting the message, the mail can be released from quarantine and passed on by issuing:
amavisd-release jBRiR2sOcpbz
where:
jBRiR2sOcpbz is the quarantine ID.