Machine Gun Mail Relay Attacks

Currently reading
Machine Gun Mail Relay Attacks

Operating system
  1. Linux
  2. Windows
Mobile operating system
  1. Android
I've been running my Synolgoy NAS and it's email services for over 3 years now and I am now seeing many "machine gun" attacks for mail relay on a regular basis. I know that Synolgoy has a lot of good settings to keep us from creating open relays and avoidance but having a 1,000 hits a minute for relay can be stressful on infrastructure. Looking at the settings in connection policies I was wondering what some other folks are using to "blacklist" abusers?

Currently we aren't very active with E-mail itself only about 30 to 50 email an hour is sent/received though the NAS so I was thinking about ticking concurrent connections and using the default value of 50. Also ticking Building more connections than the limit for one minute but struggling to come up with the number of connection per minute that would be appropriate.

Thanks in advance for any guidance.


Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Welcome to! is an unofficial Synology forum for NAS owners and enthusiasts.

Registration is free, easy and fast!

Trending threads