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13 Glossary

13.1 Bounce Management

OpeEMM's automated bounce management provides you with the capability to keep your mailing lists clean and up-to-date automatically. A bounce message is an error message, which is sent from a mail server on the recipient's side to the sender if an email is not deliverable. Bounce management administers emails which are undeliverable temporarily (soft bounce) or permanently (hard bounce). It also filters error messages and autoresponder mails.

OpenEMM does not treat all hardbounce messages reported by remote mail servers as hardbounce. In fact, some messages are only treated as softbounces, although their bounce codes starting with 5 would indicate a hardbounce.

The reason for this kind of ignorant behaviour ist intentional, because some mail servers are not properly configured regarding the generation of hardbounce messages and mistakenly report permanent delivery errors - some even by intention to pretend that certain email addresses do not exist. If OpenEMM would handle those fake hardbounce messages as real hardbounces email addresses of existing recipients would be disabled. As result, we only try to accept bounces as hardbounces which are really proved to be hardbounces.

If you want to modify the bounce management of OpenEMM, file bav.rule in directory /home/openemm/lib is the right place. This file lists in section [hard] bounce messages which are recognized as hardbounces, and section [soft] lists bounce messages recognized as softbounces. The messages are formatted as regular expressions to allow, among others, the use of wildcards. You may add your own set of messages here.

By the way, if a hardbounce message is recognized as a softbounce even if it is a real hardbounce, this is not a problem. Because a real hardbounce is reported for each mailing again and is counted as a softbounce each time, it will be finally caught by the softbounce scoring of OpenEMM and converted to a hardbounce in the end.

13.2 DNS

DNS is the abbreviation for Domain Name System. This system forwards requests directed to a FQDN to a certain IP address. Each entry in the DNS maps the IP address of a server to a human readable address. Example: In place of the IP address 83.169.23.100, which points to the AGNITAS website, you may use the DNS address www.agnitas.com, which is much more convenient (for a human).

13.3 FQDN

A Fully Qualified Domain Name (FQDN) links to an IP address of a server. The FQDN may be composed of letters and numbers and by using this option nobody has to remember the difficult number sequence (IP). A FQDN is divided in three levels:

  • The affix of the domain is the Top Level Domain (TLD). Example: com, org or de
  • The domain name will be inserted in front of the TLD. Example: agnitas
  • The FQDN starts with the hostname. For webpages this is very often www

Example: The FQDN www.yourdomain.com is composed of

  • www = hostname
  • yourdomain = domain name
  • com = TLD

As you can see, the FQDN consists of the hostname, the domain name and the top level domain separated by dots. The combination of domain name and TLD is commonly referred as domain. The FQDN can be expanded by a subdomain (like miami). The subdomain will be inserted between the hostname and the domain. Example: www.miami.yourdomain.com .

13.4 Softbounce Scoring

If an email address generates lots of softbounces (temporary delivery problems) this is actually an indication that the email address is undeliverable permanently (hardbounce). OpenEMM provides softbounce scoring to identify those email addresses and to convert them to hardbounces.

The rules for converting a softbounce to a hardbounce work like this:

  1. Select all email addresses in the softbounce table which generated more than 40 softbounces and where the time-lag between the first and last bounce is longer than 30 days.
  2. If no mail opening or link click was registered within the last 30 days for an email address which matchs the before-mentioned conditions, this address is flagged as a hardbounce.
  3. If at least one opening or click was registered within the last 30 days, this address is removed from the softbounce table, i.e. its bounce count is reset to zero.

Third Party Licenses

OpenEMM relies on several great open source frameworks, libraries and tools. In order to give due credit to those fine projects, you will find the individual licenses of the open source projects used by OpenEMM in subdirectory /home/openemm/webapps/emm/licences.