Re: SMPTD not responding on connect, from SOME servers.

[Fabio Busatto <fabio.busatto@sikurezza.org>]

On Fri, Dec 22, 2006 at 01:12:47PM +0100, Ander Tobias wrote:
> Hello,
> I've got an interesting problem with a qmail-smtpd.
> When some servers  connect to It they don't even got an smtp banner (220) but 
> some other do get it. (tested in a normal telnet session of course))
> It seems that all legal servers do have a problem connecting to my machine, 
> but all illegal that sends tons of spam is able to connect.

Reasons could be more.
First of all, some questions:

- do you connect to SMTP and then don't receive the banner or you cannot 
connect at all? (maybe network congestion or firewalling issues)
- does tcpserver spaw the qmail-smtpd process or not? (maybe dns resolving 
issues)
- is your concurrencyincoming value big enough to let you some free slot to 
connect? (maybe configuration issues)

If you point us to your server (if directly connected to the Internet) we can 
provide many more tips.

Bye
Fabio