If you have reached this page, it is probably because your email to our site has been returned and has referenced this page. This site utilizes several measures to avoid receiving unwanted unsolicited "junk" email, specifically those related to sales, marketing, fund-raising, polling, political, etc. These techniques occasionally result in rejection of legitimate email, and if this is the case we apologize for the difficulty.
The following are messages you are likely to receive, and what they mean:
Client host [{ip-address}] blocked due to Spamhaus SBL/XBL
This indicates that the mail server you are using (likely an Internet provider's) has been listed on the Spamhaus Block List (SBL) or Spamhaus Exploits Blocklist (XBL) operated by the Spamhaus Project.
These are well-maintained lists of servers that have shown a history of sending unsolicited bulk email or participating in the distribution of malware via email. The Spamhaus Project's lists tend to be less aggressive than other similar lists, and responds quickly to requests to remove servers that have been incorrectly listed (or that have had the issue resolved). Your email address is not listed, but rather the server that handles your email is on the blocklist.
In order to resolve the problem you must have the person or organization responsible for handling your email check their server's address at the Spamhaus web site and follow the de-listing procedure on their site.
Note that many servers utilize the lists from Spamhaus, and your email is likely to be blocked by other servers (not just this one).
Sender address rejected: reason
Client host rejected: reason
Unless the reason is otherwise listed below, the reason you have receieved this message is because you are using an email address or server that has originated email that was in violation of some policy here (see the reason provided).
Most of the time the reason falls into one or more of three catagories: Spam (unauthorized sales or "junk" email) was sent from the email address or server, marketing or similar emails continued to be sent after following your organization's preference process, or the preference process was inoperable or inadequate. Under some conditions email addresses are blocked due to abuse of services.
This is a serious situation that you, your organization, or a vendor you are contracting with needs to resolve. For this action to be taken, a fair amount of effort was already expended to resolve it amocably. If you are a business, you have likely already lost a customer as I will not conduct business with those who insist on abusing communications mechanisms as a marketing or sales tool (especially after wasting time trying to follow a non-functional preference process).
Recipient address rejected: User unknown
The email address you have attempted has been disconnected or is no longer in service. Please check the email address and try to send again.
Seriously, the user portion of the email address is not valid here. Please check the spelling (including numerals and letters that may appear the same, such as the number "1" and the letter "l" or "i") of the email address.
If you are a business that has previously sent spam to the email address you were given, then it is possible that the email address was removed because the person no longer wants to hear from you.
Message rejected due to: SPF fail - not authorized. Please see {url}
The email address you are using has a domain portion that has implemented Sender Policy Framework (SPF), and a server you are using is not listed properly as being permitted to handle email for your address.
If you are already familiar with SPF, you probably already understand what is wrong and how to resolve the problem. If you do not know what SPF is, or why it applies to your email address, you will need to contact the person or organization who assigned your email address and have them correct the situation.
gc2.kloepfer.org has been deprecated - use kloepfer.org
The subdomain gc2.kloepfer.org was removed many years ago and all users were moved under kloepfer.org. If you are sending to {user}@gc2.kloepfer.org, try re-sending to {user}@kloepfer.org instead, or visit the send me mail web page.
Relay access denied
You likely attempted to send a message to a specific host within kloepfer.org or kloepfer.net, and this is not permitted.
The only other time this happens is when someone is actually attempting to bypass legitimate restrictions on the site. If this is you, be aware that these are all logged, and you run the risk of legal action and/or having your system(s) listed on spam blocklists.
This user cannot receive mail
You have attempted to send mail to a user at this site that is unable to receive email. Please check to make sure you are sending to the proper email address, otherwise contact the person by some alternate means to get a correct email address.
See https://www.kloepfer.org/sendmemail.html
This messsage occurs when email is sent to the webmaster address. Due to the number of spam messages sent to "webmaster," the decision was made to remove this. Please follow the instructions at the page listed above.
If you are legitimately attempting to send person-to-person email that does not fall into the one of the categories previously defined as "junk" to someone in the @kloepfer.org or @kloepfer.net domains, a special email address has been provided that will allow you to make contact to attempt to resolve the issue:
Before using:
Your communication MUST NOT be for any of the following reasons: Marketing or sales contacts, polling, political canvassing, religious, activism, or any related purpose. If you are at all unsure whether your communication would be interpreted as being in one of those categories, then it probably is, and you would be advised to not send the email.
Understand that the communication will be read by the system administrator responsible for the servers that handle @kloepfer.org or @kloepfer.net, and this may not be the same person you are attempting to contact.
Note that this email address is only for the purpose of resolving email communication difficulties. It is not a general contact address, and will be changed frequently. Please do not put this into your contact list as you will end up having future difficulties that will result in frustration for all involved parties.
If you have read and understood all of the above, you may send to the user mailblocked25601 at the domain @kloepfer.org.
Again, our apologies for any difficulty the e-mail blocks have caused. Please understand that we do value e-mail messages from people, and that receiving an inordinate number of spam messages creates an environment where we cannot easily sort out the good messages from the bad ones.
Last revised:
Mon Jun 9 15:37:26 CDT 2025
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