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When I try to send email from local mail server to Hotmail, the message is not being received by the hotmail account because my mail server IP address is listed in the XBL list.

How can I remove my mail server from the Hotmail XPL list?

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is it a dynamic ip address? – Journeyman Geek Jun 5 '11 at 11:35

If you are trying to send from a home-class Internet service using a DHCP IP address, the entire subnet has been listed as DHCP by your ISP (they are required to do this), and that has been picked up by the blacklists. If you have a DHCP IP address, another major issue is that your PTR DNS record (used to make sure that you are who you say you are, and not a spammer, who is relaying) does not refer back to your mail server, but to your ISP's DNS host name they have given your IP address. That problem will also get your mail blackholed at Hotmail and AOL, among others.

In that case, your only option is a "smarthost", which is a relay that you send your mail through, and it delivers it on your behalf. These are not blacklisted and are configured with a proper PTR record, so the mail goes fine. Your ISP may have an SMTP server smarthost that you can relay though, but unless you have a business account (I actually have a business-class Internet package that I use with DHCP and DDNS, so I relay through their business-class SMTP relay smarthost), SMTP servers for home-class Internet packages have all but gone away.

If that is the case, you Google "smtp relay service" (minus the quotes), and find one that you can pay for. They are typically $20-$50 per year.

I have been doing IT professionally for 17 years, but e-mail is my specialty.

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+1 for this good answer. note: you could also relay trough a "white list" e-mail account (e.g. gmail) – udo Jun 5 '11 at 13:30
udo, that kind of negates a lot of the reasons to have your own e-mail server. – KCotreau Jun 5 '11 at 14:06
correct. I was mentioning relaying because to me it looks like he is using a mail server from his local machine... – udo Jun 5 '11 at 16:09

Check if you're listed here: Spamhaus Blocklist Removal Center. There's another blocklist checker here.

Note that Microsoft says:

If Microsoft believes that unauthorized or improper use is being made of any Service, it may, without notice, take such action as it, in its sole discretion, deems appropriate, including blocking messages from a particular internet domain, mail server or IP address.

So basically, you probably did something wrong.

If you are blocked, go through the removal process, but I'd strongly suggest checking whether one of your computers is infected and sends out spam without your knowledge. There is a reason why you're on a blocklist.

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They did not have to do anything wrong. It is simply because they are on a DHCP subnet. And as a side note, you cannot get the blacklists to remove a DHCP IP address via their removal process. – KCotreau Jun 5 '11 at 13:10
@KCotreau Thank you for the note. I hadn't seen this from a "consumer" side before, we only had these issues from a corporate network. – slhck Jun 5 '11 at 14:00

If you're on a blacklist you're either sending spam, or sharing a subnet with someone who is.

Since you mention using a local mail-server it sounds like your ISP has chosen not to block outgoing SMTP-traffic, which makes it all the more likely that a malicious (or virus-infested) user was sending out enough spam for the subnet to be blacklisted.

First of all, check a couple of public blacklists for your IP-address (I highly recommend using this tool.) If you're listed you should find an SMTP relay, your ISP probably provides one.

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the reason for this is because you are sending the mail from your localhost via the ISP. a lot of spammers do this. this is the reason why dynamic sub-nets of ISPs are on the "black list" for outgoing e-mail.

because this is a security setting handled by the service provider, you have to check with hotmail directly.

you could start here

alternatively, you can do the folowing:

  • use a mail server from a "white list" IP (which is not published either).
  • relay your mails through a "white list" account (e.g. a gmail address)
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It is not the ISP that is blacklisted. The ISP has reported those subnets as dynamic to, and the blacklist has added any reported DHCP subnets to their list. If they have static subnets for business-class service, there is no problem. – KCotreau Jun 5 '11 at 13:07
thanks for detailing this. will update accordingly. – udo Jun 5 '11 at 13:25

My 2 cents: check for server IP blacklisting here and here

Check that server isn't sending spam.

Then go here fill the form, and wait for response.

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Microsoft relies on various authentication filters to determine if an email is spam or not.

Common industry practices include reviewing email for the presence of a SPF Validation, Sender ID and DKIM records within email received.

The Sender ID Framework is an e-mail authentication technology protocol that helps address the problem of spoofing and phishing by verifying the domain name from which e-mail messages are sent.

SPF (sender policy framework) is essentially an extra DNS record that directly specifies where remote mail servers should be expecting to receive mail from.

DKIM (DomainKey Identified Mail) is a newer implementation of the older DomainKeys system, which is essentially a more complex approach toSPF/mail verification, that requires mail to be signed with a private key, and checked against a public key found in the DNS record. This essentially acts as a more secure version of SPF.

You can send an email from a to when sent, an email will return stating the verification of DKIM, DomainKeys, SPF, SpamAssassin, and Sender-ID.

However, in recent months, I have found that despite including these elements with emails sent out, Microsoft was still ditching legitimate emails. Microsoft recommended using the services of Sender Path, which is paid-service certification service.

However I found that once the recipient had our email address listed as a saved contact, they received our emails fine. So I’ve created a vCard for our company and urged our customers using Hotmail or Windows Live email services to save the vCard as a contact to ensure that our emails get delivered correctly.

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