Hotmail blocking emails from our Exchange box since swapping to new IP

[TheFopp]

Hi all

 

Hoping someone might be able to help. Our Exchange 2010 box has been running OK for some time. On Friday we went live with our new leased line (which obviously meant swapping IP addresses). Domain and MX records etc, all swapped at ISP, and all working fine. Emails send out and are received. Everyone can happily log in to OWA from outside.

 

One problem though, since the swap, we haven't been able to send emails to Hotmail/Outlook.com accounts. Have had a look at https://postmaster.live.com/snds/ and it is showing our new IP as blocked due to email harvesting.

 

As far as I can tell there is no spam being relayed by our server, and it seems odd that we weren't blocked before the IP change. Checked HELO which seems fine. Were not listed on any Blacklist sites etc. As far as I can DNS and Reverse DNS are all fine. The only contact there seems to be to find out why this has happened is the online form at https://support.msn.com/eform.aspx?productKey=edfsmsbl2&ct=eformts which just sends me back an email saying:

 

More information needed

xx.xx.xx.xxx (our IP address)

There are indications that the above IP(s) are engaged in namespace mining. Outlook.com is blocking all email sent from this IP.

 

and tells us to correct the problem and you must stop the behavior described above.

 

Not a lot of help and no information to go on really.

 

How can I solve this?

 

Any help would be appreciated.

 

Cheers

Adrian

[Oaktech]

have you had a look at MX toolbox for blacklisting?

 

We had a random one like this the other day and we just emailed in and said who we were and explained that we had swapped IP's last summer and the IP we had swapped to was recycled and that we would pretty please like them to stop blocking us. The block was gone in 24hrs.

[TheFopp]

Hi Oaktech. We've checked MX Toolbox and no blacklisting there. Who did you contact and what was their email address as I can't find any relevant contact details on the Microsoft Postmaster site.

[Oaktech]

Right, I can't find the email we used last summer...

 

But the process went a lot like this guy...

 

Howto Remove (delist) your mail server IP from Hotmail, Live.com and MSN mail server blacklist | Walking in Light with Christ - Faith, Computing, Diary

 

Also try seeing if you are black listed here: BarracudaCentral.org - Technical Insight for Security Pros or here https://spamrl.com/

[box_l]

As you have a leased line I presume you have multiple IP addresses.

 

First check that your mail server is not causing the issue, then confirm which IP has the blacklist issue.

 

Check all your IPs.

 

Outgoing mail may not be going out of the address it comes in on.

 

Configure, (or get whomever manages your firewall), to push mail out of an IP that is not listed.

 

This will give you the opportunity to concentrate on finding the culprit that is causing the blacklist issue.

 

BoX

[pickman]

This happened to me this morning seems a common thread at the moment.

 

 

Took me 3 hrs to resolve.