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What if your email is being rejected by craigslist email servers

Is your email is being rejected by our servers with a message like this?

 554 5.7.1 <yourhost.yourdomain.com[10.10.10.1]>: Client host rejected: please_use_SMTP_relay_of_your_isp,_or_setup_non-generic_dns.

In an effort to curb abuse of our email servers and limit the amount of spam inflicted upon our users, craigslist does not accept email from computers with dynamically assigned IP addresses, or hosts that have generic DNS setup.

If you get the above message, here's what to do:

The easiest solution is to use the mail server of your ISP to relay your email, as they almost certainly have their DNS setup properly in the way we would like. If you're not sure how to setup your mail client to do this, please contact your ISP.

For tech folks that want to run their own mail server:

If you have a static IP address and want to be able to send email through your own mail server, you will need to contact your ISP and have them setup non-generic DNS for your IP address. Usually this is done via a PTR record. Note that you'll need a matching A record. Again, the easiest solution for most end users is to route their outbound email through the mail server of their ISP.

If these suggestions don't work, some people find it easiest to use one of the many free web based email systems.

What is generic DNS?

When you make a connection to our servers, we use your IP address to perform a reverse lookup to find the name listed for your computer in the domain name service.  We consider you to have generic DNS if the hostname returned contains:

  • An IP address
  • The words pool, dhcp, dynamic
  • The words dsl, ppp, pub
  • The words server or host
  • The words dial or dialup
  • The words cable or modem
  • The words host, client, node, cust, customer
  • Any other indicators that the hostname is not specific to you or your organization

Still not working?

If you have a static IP address, run a mail server and do not have generic DNS, and are continuing to run into trouble, please send email to postmaster@craigslist.org. Be sure to include the complete headers and rejection message, so that we're able to determine exactly what is happening.