POP3 Service

[Chëëzmønkëy]

I have the SMTP working fine, but whenever you try to send to a mailbox on the domain you get the following error:

Sent <<< MAIL FROM:<xxx.xxx@xxx.co.uk> SIZE=3379 Received >>> 530 5.7.3 client was not authenticated

Unable to deliver message to <bum@cheez.servebeer.com> (and other recipients in the same domain).

The mailbox is valid.

[silencio]

Is anonymous access enabled for the smtp server instance?

[Chëëzmønkëy]

i do not believe so, i will check in a minute (its my home machine and ia m at work.)

[silencio]

In order to recieve any mail from outside your domain you need to enable anon access on the smtp server instance. This is ok as long as you have your relay settings correct. If your bent on security you can block off entire A class domains from places like amsterdam and asia. Here's why.

Spammers can use your server to bounce mail even if relaying is off. Here's how it works. First, they create a piece an email addressed to any non working address in your domain. Second, the put the victims email address in the from field of the email. Third, they send it. What then happens is your smtp server recieves an email for an unknown address. It then attempts a reply in the form of a DNR to the "from" address which is really the intended spam recipient. So, your server winds up playing the devil. This is why blacklists are nice but I haven't seen one for windows server 2003 that I like.

So, I just see that happen once in my logs then I add the entire A class network from the offending address to the "denied" list of machines able to "connect" to the server. I'm never going to get business relevant email from asia or amsterdam anyway.

[BIGGS]

you could check with you isp and make sure that the address or domain your attempting to send mail to is not on their blocked senders list

[silencio]

you could check with you isp and make sure that the address or domain your attempting to send mail to is not on their blocked senders list
Yes. It's always good to live in a good part of the internet.

[Chëëzmønkëy]

Yes. It's always good to live in a good part of the internet.


i have applied anon access to SMTP, works great now (yay!)

however i am now an open relay :(

[silencio]

i have applied anon access to SMTP, works great now (yay!)

however i am now an open relay :(
Why are you an open relay? You don't need to be. Can you explain your setup a bit?

[Gollo]

Just block port 25 from the internet (unless you plan on sending mail from outside of your home network). Also isn't there an option in most email clients to request authentication before using the smtp server? (I'm just guessing at some of this stuff as I have just setup my first 2k3 server. I'm much more comfortable with linux).

[silencio]

Just block port 25 from the internet (unless you plan on sending mail from outside of your home network). Also isn't there an option in most email clients to request authentication before using the smtp server? (I'm just guessing at some of this stuff as I have just setup my first 2k3 server. I'm much more comfortable with linux).
If you run a public server (need to accept email from outside your network) you need anon access. But, the way smtp is designed you can forward to internal domains and drop mail not intended for domains you don't run.