home | list info | list archive | date index | thread index

Re: My ongoing email server adventure...

On Sun, 9 Feb 2025 14:01:21 -0500
Tug Williams <tug [ dot ] williams [ at ] gmail [ dot ] com> wrote:

> __blocking annoying ip address__

> A few days ago postfix started getting a connection from a single IP 
> address, about 3x per minute. All failing.

This is part of the background noise of the Internet.  I don't even bother
checking my logs for this sort of thing any more unless I notice a load
problem on my MX host.

> What is the point of flooding my server like this? I haven't enabled
> AUTH from outside the server. Do they think I will make the error go
> away by granting them access?

They're probably scripts that dumbly keep trying,

> Is this someone sticking a metaphorical fish behind a metaphorical 
> radiator, so the ip address becomes useless for the next user?

The IP address might already be compromised by the attacker.

[...]

> __disable VRFY__

> By default my Gentoo setup enabled VRFY (allowing client to verify if
> an email address exists). I disabled it. Why would I leave this
> enabled? In what way does it benefit me?

There's no benefit and no real-world SMTP client I'm aware of uses VRFY
anyway.

> __sendEmail__
> I installed sendEmail 
> (http://caspian.dotconf.net/menu/Software/SendEmail/), as I found 
> netcatting directly to port 25 from bash didn't work. SendEmail
> works, and makes my bash script look more like a script. There seem
> to be multiple tools like this. Preferences?

Why wouldn't you just use /sbin/sendmail (or perhaps
/usr/sbin/sendmail) which is Postfix's message submission agent?  That
way, if for some reason Postfix isn't listening on port 25, your email
gets queued anyway.

Regards,

Dianne.

To unsubscribe send a blank message to linux+unsubscribe [ at ] linux-ottawa [ dot ] org
To get help send a blank message to linux+help [ at ] linux-ottawa [ dot ] org
To visit the archives: https://lists.linux-ottawa.org