Spamdyke is a spam protection program that filters incoming messages at the SMTP level by blocking connections from mail servers identified as spam sources or that match certain reverse DNS validation rules and RBL Checklists.
All domains hosted with 2Large Networks have full administrator access to WHITELIST & BLACKLIST on a per domain basis.
2Large Networks uses the following methods to determine whether a sending server can be identified as a spam source:
1. Reverse DNS check
Every server on the internet should have a reverse DNS entry, especially mail servers.
Our mail server checks for reverse DNS entries. Any email coming from a server without one is blocked. This stops a lot of email from servers that shouldn't be sending email, such as virus-infected home computers on ADSL connections.
2. RBL Checks (Lists of known spam hosts).
Spamdyke checks the sending server IP address against several databases of known spam hosts. In case the sending server IP is listed in any of them, the message is blocked.
3. DENIED_IP_IN_CC_RDNS
Your server's reverse DNS entry contains its IP address and ends in a two-character country code. For example, if your IP address is 100.10.20.30 and your reverse DNS entry is 100.10.20.30.example.com.us, our server is going to block your email. IP addresses in reverse DNS entries usually indicate servers that shouldn't be sending email -- just the kind of server a spammer would use.
If you have recieved any of the following email notifications while sending to 2large Networs or our hosted client, Please contact us to resolve this issue for you as quick as possible.
| syslog code | SMTP message |
| DENIED_ACCESS_DENIED | Refused. Access is denied. |
| DENIED_AUTH_REQUIRED | Refused. Authentication is required to send mail. |
| DENIED_BLACKLIST_IP | Refused. Your IP address is blacklisted. |
| DENIED_BLACKLIST_NAME | Refused. Your domain name is blacklisted. |
| DENIED_EARLYTALKER | Refused. You are not following the SMTP protocol. |
| DENIED_GRAYLISTED | Your address has been graylisted. Try again later. |
| Refused. Your reverse DNS entry contains your IP address and a country code. | |
| Refused. Your reverse DNS entry contains your IP address and a banned keyword. | |
| DENIED_OTHER | The text returned by qmail (or the downstream filter that generated the rejection). |
| The text returned by the DNS RBL (if any) or Refused. Your IP address is listed in the RBL at name. |
|
| DENIED_RDNS_MISSING | Refused. You have no reverse DNS entry. |
| DENIED_RDNS_RESOLVE | Refused. Your reverse DNS entry does not resolve. |
| DENIED_RHSBL_MATCH | The text returned by the RHSBL (if any) or Refused. Your domain name is listed in the RHSBL at name. |
| DENIED_RECIPIENT_BLACKLISTED | Refused. Mail is not being accepted at this address. |
| DENIED_REJECT_ALL | Refused. Mail is not being accepted. |
| DENIED_RELAYING | Refused. Sending to remote addresses (relaying) is not allowed. |
| DENIED_SENDER_BLACKLISTED | Refused. Your sender address has been blacklisted. |
| DENIED_SENDER_NO_MX | Refused. The domain of your sender address has no mail exchanger (MX). |
| DENIED_TOO_MANY_RECIPIENTS | Too many recipients. Try the remaining addresses again later. |
| DENIED_UNQUALIFIED_RECIPIENT | Improper recipient address. Try supplying a domain name. |
| DENIED_ZERO_RECIPIENTS | Refused. You must specify at least one valid recipient. |
| FAILURE_AUTH | Refused. Authentication failed. |
| FAILURE_TLS | Failed to negotiate TLS connection. |
| TIMEOUT | Timeout. Talk faster next time. |
| UNKNOWN_AUTH | Refused. Unknown authentication method. |
If you require further assistance, please contact us
Immediate solutions for a range of security challenges, including the following: