SMTP - A lot of invalid recipients in log.

[jjjax0330]

We are running an x700 and recently, I've been noticing a real lot of smtp-proxy(999) 999.999.999.999 172.16.1.5:25 rcpt to: denies invalidm recipient address "xxxxxx@general-trading.com" in our log. The ip addresses that they are coming from are constantly changing and the email addresses are for our domain but are all invalid addresses so they aren't getting through but it seems like we are getting attacked and can be slowing down our a connection a little. I've done tests to make sure we're not being used as a relay and it seems to be doing it's job but it has really increased to the point where we are constantly getting the above messages. Does this sound like a possible problem on our end or is it just what we've got to deal with because of all these spammers? Thanks, Joe

 

[xwire]

Have you tried to use Filtered SMTP instead of Proxied SMTP? I seem to recall the Proxied SMTP having some sort of problems. But there may be people out there with good luck using the Proxied SMTP. I had to switch to Filtered SMTP after numerous searches on Watchguards site and their tech support.

 

[jjjax0330]

Thanks for the reply. We do use filtered-smtp for outgoing but just smtp for incoming as I believe Watchguard recommends.

 

[xwire]

ok, I do think you are getting hit by spammers. I get tons of email to our domain for someone like joeb@mydomain.com, even though joeb isnt employeed here. Behind the watchguard we have another solution that eats those. But yes your getting hit by spammers