Using a dynamic IP address
This is an example bounceback where the sender has attempted to send email from a dynamic IP address.
Diagnostic-Code: SMTP; 554 DNN4Less
is not accepting mail from [ Client host ; 220.127.116.11 ] at this time. (dnsbl.sorbs.net; Dynamic IP Addresses See: http://www.sorbs.net/lookup.shtml?18.104.22.168). Contact abuse@DNN4Less
.com if you believe this to be in error.
Due to the increase in trojans and virus's sending spam from infected machines, almost all emails originating from dynamic IP addresses are spam. To protect our customers interests we are not able to accept email directly from a dynamic IP address. If you are using a dynamic IP address please ensure that you are sending email via a designated SMTP server. This server will either by provided by your ISP or by the provider of your email service. If you are using DNN4Less as your Internet service provider, or are sending email from an advanced mailbox you can use DNN4Less SMTP servers to send email.
Using a static IP address
The following example bounceback has been returned as a complaint regarding unsolicited email has been reported as originating from this IP address.
is not accepting mail from [ Client host ; 192.168.111.52 ] at this time. Please contact abuse@DNN4Less
.com quoting this full error message.
dnsbl.sorbs.net; Spam Received withing last 12 months See:
http://www.sorbs.net/lookup.shtml? 192.168.111.52 Spam Received Recently See:
If you are the administrator of the listed IP address
This email has been returned as a complaint has been made regarding unsolicited, or abusive email originating from this server. Additionally this server may be listed as an open proxy, relay or may be an exploited machine. As the administrator of the IP address listed in this message you should ensure that no unsolicited email is sent from this IP address then contact the company that has you listed. This can be found in the link provided within the returned email. You can then request that they remove your IP address from their records.
If you are sending email through a designated mailserver
Any internet service provider who does not actively take precautions to limit the likelihood of unsolicited email being sent through their servers runs the risk of having the IP addresses involved blocklisted. If your internet service providers mail server has been identified by a blocklist as a source of unwanted or abusive email you should contact them directly. They may require the header of a bounced email to investigate fully.