[Intrusions] SMTP relay server tagged by IDS

[Walzer, Jeff]

Our SMTP relay server is being tagged by our IDS with the TCP SYN Host
Sweep on Same Dest Port alert. Here is the raw message:
 
xxx.xxx.xxx.xxx/3307 --> 12.129.199.35/0 TCP TCP SYN Host Sweep On Same
Dest Port,NR-3030/0,Risk Rating:21
 
The weird thing is that the destination port is 0 - is this standard
behavior and a false positive or something I should dig deeper into?
 
Thanks...
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