Unsolicited Bulk Email abuse - Exchange 2003

[rob998]

We have sudenly lost the ability to send external e-mails! Eveything has been fine for months and nothing has changed on the exchange server. Then last night e-mails I was sending were getting returned with the following message:

 

Your message did not reach some or all of the intended recipients.

 

Subject:

Sent: 31/03/2010 9:14 AM

 

The following recipient(s) could not be reached:

 

**name**@domain.com on 31/03/2010 9:14 AM

There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.

<**server-address**.internal #5.5.0 smtp;550-Your server is a current source of Unsolicited Bulk Email abuse. Please>

 

The above was just a test but it happens with any external address and any user.

 

I have used a website called MX Lookup Tool - Check your DNS MX Records online - MxToolbox to check if we are on a blacklist but we are not on any of them.

 

I have logged a call with our ISP about this but if you guys have any suggestions I would be greatful.

[dwhyte85]

Was this for every e-mail or just to a specific recipient?

[rob998]

I have tried a few recipients:

 

*@hotmail.com

*@ntlworld.com

*@lea.sch.uk

 

All have come back with the same reply. I have done this using several user accounts :-(

[AngryTechnician]

Are you on a fixed IP, not dynamic? It's unlikely you would be on a dynamic address, but if your IP has changed recently you may have inherited one used by spammers in the past.

 

Have you double checked your relay authentication is working correctly for external connections?

 

It also is not impossible that another of your ISP's customers has caused a portion of their netblock to be banned and you're part of it. This is up to the ISP to resolve so raising it with them is the right approach. If your ISP's own SMTP server has not been blocked you could configure your Exchange server to route through that as a smart host temporarily.

Edited March 31, 2010 by AngryTechnician

[rob998]

HELO please-read-policy.mxtoolbox.com

250 **server-name**.internal Hello [64.20.227.133] [156 ms]

MAIL FROM:

250 2.1.0 [email protected] OK [140 ms]

RCPT TO:

550 5.7.1 Unable to relay for [email protected] [140 ms]

QUIT

221 2.0.0 **server-name**.internal Service closing transmission channel [140 ms]

 

That is the result of a relay test from mxtoolbox.com

 

We are routed through our ISPs Smart Host. ISP are looking into it but I don't think any IP adresses have changed otherwise we would be able to receieve inbound mail.

 

It happened around 8pm last night, nothing changed on my server so something external is to blame here i'm thinking!

[pwds]

If you're using a smart host I'd be looking at another customer of that ISP as the culprit for sending spam- probably due to a compromised server.

 

Of course not being the ISP I'd actually be asking the ISP to look at that.

 

Can you fall back on to directly relaying mail for the time being until your ISP gets their act together?

[rob998]

Turns out our ISP had put a manual block on our IP using their Smart Host. Not sure what the reason is for doing that. Hopefully I should be back up and running today.

 

Rob

[rob998]

Working now

[kmount]

Turns out our ISP had put a manual block on our IP using their Smart Host. Not sure what the reason is for doing that. Hopefully I should be back up and running today.

 

Rob

 

"Manual Block" - Did they not think to yanno, inform you of this?

[pwds]

Was a reason given? Have you run a open relay check against your server?

[MxToolBox]

Thanks for recommending our DNS tools, we are always interested to see what other tools you are using in conjunction with ours.

 

Let us know if you think our website is missing any tools and we will look at adding them.

 

Thank you,

@MxToolBox

[kmount]

Thanks for recommending our DNS tools, we are always interested to see what other tools you are using in conjunction with ours.

 

Let us know if you think our website is missing any tools and we will look at adding them.

 

Thank you,

@MxToolBox

 

Welcome to Edugeek,

 

Your site has no doubt helped many other people (myself included) over the years, please stick around as no doubt your knowledge will be helpful to people on here.

 

Thanks

 

Kim

[MxToolBox]

Welcome to Edugeek,

 

Your site has no doubt helped many other people (myself included) over the years, please stick around as no doubt your knowledge will be helpful to people on here.

 

Thanks

 

Kim

 

Thanks so much! We will definitely be chiming in time and again.

 

Thanks,

@MxToolBox