Blank Mail originator 1

[emoongq]

Hello, I've an issue with my Exchange 5.5 server, I can see in the outbound meesages queue a big list of blank originators, they appear just like that: <>, I know there is no more support for this verison but maybe somebody knows how to prevent this issue, it is generating a lot of traffic in my router.

Tks

 

[cmeagan656]

It sounds like a Reverse NDR attack. Read this FAQ faq10-5018.

Cheers.

 

[emoongq]

I already did it and it worked the issue now is that part of my mail messages are not delivered.

Tks

 

[zbnet]

You can delete these messages from the queue if that would help.