Here's a nice one...
I get an email with an alert - ISA Server alert: An unknown SMTP command was used.
PQODTNQUOU2OW1NVQKK3RDPTEDONTGXFE2BPE+YW7AM41MUFDOLLZYOK5FZZTUBY1LWHQQ0KSMX8
And I also got one with:
"THIS IS
Some kind of new buffer overflow attempt? Its all truncated, so I wonder...
Here it is again:
R6HKBJFHBQTMRDKMBPBJNC6Q1A9FKG58PV/LXYS7UCWYOQU6MF04RQX5JHA85LA+WRCTQUUVUO
IG
Cause:
http://blog.justinho.com/Weird+SMTP+Commands.aspx
Stupid scanning components. Do the packet capture for the traffic and just blacklist the IP range. =)