exchange 5.5 and exchange pop3

[ADoozer]

first off, i am not the network guy, he's on holiday until 17th july. im just the lucky mug whos trying to get it back working.

setup:

ADSL modem->hardware firewall->LAN

2 servers on the LAN, Vic running exchange 5.5 and Bob runnning exchange pop3.

both incoming and outgoing emails are routed through exchange pop3

problem:

on wednesday 5th july, the servers went down. after a reboot all seemed well. however.

internet connection - working
incoming email from internet - working
outgoing email to internet - not working
internal email (send and recieve) - working

i looked over the message logs in exchange pop3 and found over 36000 entries, the majority of which were mails to an adress at netbank.com.br and message not deliverable, these seem to stop at the point the server was rebooted. (note: these were logs not queues)

anyway, i called the ISP and they said they werent blocking our outgoing email (apparently they have done it in the past) and that the issue was on our network.

ive updated all the virus definitions (although it is set to update automaticaly every day) and scanned, but found no virus/trojan.

so now im out of ideas.

any input greatly appreciated.

If somethings hard to do, its not worth doing - Homer Simpson

 

[dennisbbb]

Do a test to see if you are being blocked at your firewall from outgoing port 25. From the pop3 server, do a "telnet outside-email-server 25" test to see if you are able to get out.

 

[ADoozer]

we can connect to the smtp server using telnet.

however we cannot send mail (using the mail from: recv to: commands)

we recieve error 501 bad address syntax.

which apparently means:

501 Bad address syntax
Unfortunately, this means that your email program (or the mail server which passed the messsage on to ours) has a problem which caused it to send a badly formatted email address. This may be either the sender or recipient address.

any further suggestions?

If somethings hard to do, its not worth doing - Homer Simpson

 

[dennisbbb]

There is a bad syntax somewhere.. be it an extra space, or an extra period.. hard to tell. If you are using Exchange 5.5.

If you were using windows 2000 as the pop3 gateway, I would've tell you to turn off 8-bit Multipurpose Internet Mail Extensions, also known as 8BITMIME.

Try to manually check where the problem is by manually typing the commands from the server with the SMTP service.

Follow this procedure:

http://support.microsoft.com/kb/153119

 

[ADoozer]

hi, we tried that already.

seems the ISP is blocking the domain name, not the actual account.

the router logs gave it away when it said words to the effect "you have been blocked for sending spam email".

although the ISP deny that they sent the message.

we also have ethereal logs of the comms to and from there SMTP server (again with the same "sending spam" message).

will update in the morning when the ISP has "investigated further"

If somethings hard to do, its not worth doing - Homer Simpson

 

[ADoozer]

well the ISP finaly admited to blocking us (after 3 denials)

they also said they emailed our admin account telling us this... which they later retracted (since we checked the accounts... and they didnt send us warning).


sooo.. 6 business days with no outgoing email, wasted resources etc etc... and absolutely nothing we can do about it.

If somethings hard to do, its not worth doing - Homer Simpson

 

[zbnet]

Sure you can, you can not pay them a proportion of this month's rental for a start. Then suggest a healthy discount on some more months charges in lieu of the lost business and disruption you have experienced.

Threaten to move your account if they don't respond favourably.

 

[dennisbbb]

I would move ISP immediately due to sloppy network service. Who knows what's next.

 

[cmeagan656]

The other thing you may want to ask you ISP is why they are/were blocking your outbound mail? You say they've blocked you before. If they warned you they were blocking you the 1st time then maybe their policy is (and I don't agree with it it it is) to just block you the 2nd time.

Are you allowing your Exchange server to be used as an open relay? You said "found over 36000 entries, the majority of which were mails to an adress at netbank.com.br and message not deliverable". I know these were in your logs, not your mail queue but they may point to a security issue with your mail server.

Cheers.

 

[ADoozer]

to be honest i have no idea... i only joined the company 2 and a bit weeks ago.

the guy who built it and set it up is back on monday, so ill leave it to him to break/fix

If somethings hard to do, its not worth doing - Homer Simpson