We had an incident last month where the PCs of one or two colleagues, who were outside of our factory and were using a defined network, got infected by some kind of malware. From their PCs, more than 1,000 mails were produced per hour, causing spamming on our mail server's IP. Barracuda blocked the full mail communication. Only one to two accounts were compromised, and for that, Barracuda blocked all incoming and outgoing mails. It created a great problem for other users and our office activities. Our mail server was partially blocked for three days, which we did not expected and suffered a lot. Technically, only one or two accounts should be blocked if those are compromised. When a domain or IP is blocked, communication becomes tough, mails are bounced by receiver server. It may be a configuration issue at our provider's end, where there was a mistake in configuring Barracuda. It could also be a problem related to Barracuda.
