Suddenly blocked by Hotmail - massive problem

[Travelling Sam]

In the past week, it seems we've been blocked from sending e-mails to Hotmail accounts. We've changed nothing our end. It just seems to have started randomly, and every e-mail to a hotmail address is blocked.

I've got people looking at it our end. I've got our Mail Hosters (ukhosting.net) looking at it. I've contacted Microsoft Hotmail to request our 'blacklisting' is lifted. But it's just so arbitrary, and seemingly taking too long to fix. Too many of our clients use hotmail accounts so it's causing massive problems.

Does anyone have any wonder ideas before I start crying?

Our error messages are:

There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<ethostravel.co.uk #5.5.0 smtp;550 OU-002 Mail rejected by Windows Live Hotmail for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation problems. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, please visit http://postmaster.live.com for email delivery information and support>

 

[Subbynet]

Policy reasons...

You need to check your set-up, but I'd suspect its missing SPF records.

 

[MH-Nick]

Contacting Hotmail won't help, think how many spammers they have wanting their email address unblocked

We had this issue originally, it was the main providers like Gmail, Yahoo and Hotmail that decided to block us not for reputation reasons (ie. if we had previous spammers) but because of our setup.

Was simply resolved by installing SPF records on our name servers and DomainKeys on our mail server. If you can, try installing DKIM and ensure your rDNS is correctly setup. Though do note you can only do this if its your mail server, if not then tell your host to do it (it will be in their interest).

As a final check, enter your mail server's IP into http://www.robtex.com/ to see if other blacklists have reasons for blocking you.

 

[Dwebs-Ltd]

Contacting Hotmail won't help, think how many spammers they have wanting their email address unblocked

We had this issue originally, it was the main providers like Gmail, Yahoo and Hotmail that decided to block us not for reputation reasons (ie. if we had previous spammers) but because of our setup.

MSN Postmaster is actually not bad at all, responses usually within 3-4hrs. Their errors don't always explain issues usually blocks relate to increase in email volumes as they limit the amount of email an IP can send within a 24hr period. If you reach that limit they stop any inbound email for 24hrs.

We always get the issue with new mail servers that jump from sending 0 to 5-10k per day to hotmail. A simple form to fill out and within 2rhrs its resolved.

If you get blocked by GMail you are stuffed as they don't have any form of postmaster service so no one to contact.

 

[awebapart.com]

How are you sending your outgoing emails? Via your website's mail server or via your ISP's mail server. Whichever is the case, check that the IP address in question is not on any blacklists (e.g. mxtoolbox, barracuda).

Also examining closely the emails you are sending out - individually and the volume as a whole - and looking at the headers of the emails you are sending out, might reveal some other reasons why some servers are suspecting that your emails might be spam.

Your domain name does not have an SPF (sender policy framework) record. You can check this with this online SPF checker tool (for domain name just enter domain.com not the www part). Adding an SPF record might help the situation.

 

[James1980]

I can't help you with solving this problem, but I think I know what caused it, assuming you regularly send emails to subscribers of a mailing list.

When you are viewing Hotmail emails, there is an icon that says "Junk". Sadly, some users regard this as a convenient means of unsubcribing from mailing lists that no longer interest them, oblivious to the fact that this then secretly marks the sender as a potential spammer. If enough people do this, you go onto their blacklist. And annoyingly for mailing list admins, this is a common occurence.

 

[MH-Nick]

MSN Postmaster is actually not bad at all, responses usually within 3-4hrs. Their errors don't always explain issues usually blocks relate to increase in email volumes as they limit the amount of email an IP can send within a 24hr period. If you reach that limit they stop any inbound email for 24hrs.

Thanks for detailing that Chris, I had no idea MSN Postmaster was responsive. There was a Postmaster service that I used to use (on a larger network), I think it was Smart Network Data Services which you could check whether the server was being blacklisted on that individual domain.

 

[Dwebs-Ltd]

I can't help you with solving this problem, but I think I know what caused it, assuming you regularly send emails to subscribers of a mailing list.

When you are viewing Hotmail emails, there is an icon that says "Junk". Sadly, some users regard this as a convenient means of unsubcribing from mailing lists that no longer interest them, oblivious to the fact that this then secretly marks the sender as a potential spammer. If enough people do this, you go onto their blacklist. And annoyingly for mailing list admins, this is a common occurence.

If you send large amounts of email to Hotmail you should setup JMRP and SNDS. JMRP is a feedback loop that reports to the sender if a recipient clicks the junk button which basically means this is spam I don't want any more email from this sender etc. If you remove the addresses reported by JMRP you should be fine.

Also check your mail servers IP against https://www.senderscore.org Hotmail and various other large email providers use SenderScore for sender reputation. If your score is low you have no chance of getting email through to Hotmail.

 

[awebapart.com]

How are you sending your outgoing emails? Via your website's mail server or via your ISP's mail server. Whichever is the case, check that the IP address in question is not on any blacklists (e.g. mxtoolbox, barracuda).

If you are sending via your website's mail server then you have to check the IP address of the mail server (the one in your outgoing mailserver settings your host provided you with), this might not be the same as your web server's IP address.

In your particular case, it looks like your host hostinguk.net has several mail servers and out of them, one (mail2 .hostinguk.net IP address 217 . 194 . 210 . 212 ) is blacklisted on both mxtoolbox and barracuda. The mxtoolbox backscatter.org blacklisting mentions recent blacklisting activity on 14th Sept, which might explain the recent blocking if you are using this email server.

 

[Travelling Sam]

I can't help you with solving this problem, but I think I know what caused it, assuming you regularly send emails to subscribers of a mailing list.

Nope - not yet, no mailings at all.

Thanks for all the comments. We're still unable to deliver to Hotmail, but have a workaround which is a pain (we can send from our Spam Mail). I had a friend looking yesterday who believes that our mail goes out directly from our server, but comes in via our website / mail hoster hostinguk.net (which was obviously how our original IT guy had set it up).

We share our IP with the office next door, but they do not have the same problem, so logically it's our domain / server, not the IP address.

Our IP was blocked by Barracuda, but we had that lifted, but is not really blacklisted beyond that.

I have contacted Hotmail, no response, no change.

I will start looking at our sender policy framework (a new thing for me!), but your help is appreciated.

 

[computer storm]

So do you run your own mail server if so what type of mail server is it? is it exchage, if so you could add a smart host to the exchange to relay your outgoing mail through your hostinguk.net, but you would have to ask them if they accept relay through them. If your mail goes straight out at the moment then you are using DNS for sending mail.

 

[Travelling Sam]

So do you run your own mail server if so what type of mail server is it? is it exchage, if so you could add a smart host to the exchange to relay your outgoing mail through your hostinguk.net, but you would have to ask them if they accept relay through them. If your mail goes straight out at the moment then you are using DNS for sending mail.

Thanks CS, that was going to be today's solution.

However, today's happy news, is that suddenly, and without warning our block has been lifted. All is back to normal. God knows why. We had posted on https://windowslivehelp.com/community/15.aspx where lots of people seem to get help from Microsoft staff, but our postings were ignored. Or maybe they weren't. Either way, the problem is gone.

Thanks to everyone who posted. I'm actually going to take a lot of what has been said on board to try and prevent this happening again, as it's caused us a lot of problems.