Mass mailings

The term mass mailing may be used to refer to cases of sending a certain message to all users hosted at a site, or to all users in  some domain, or to all users in some organization unit, or to all  members (including "external" members) of some  "large" mailing list, etc.---any case where the  number of recipients is relatively "large". The purpose of the message might be one of great urgency (such as an emergency  communication), or it might be of general interest but low urgency  (such as routine announcements).

Since the MTA supports LDAP filter based (so-called "dynamic") group and list definitions, it is straightforward  to define a list or group to consist of all users meeting some criteria  (any criteria that may be specified in an LDAP URL filter). See in particular the MTA&#x27;s support of   and    attributes (or more precisely, those  attributes named by the    and   MTA options) in LDAP group entries. Or for MTA alias file defined groups and lists, see the LDAP URL membership  syntax discussed in  Alias file LDAP URL alias  values. And more complex lists can be constructed, including criteria-based sets of locally-hosted members  along with external members listed by address, or lists with  "nested" definitions of sub-lists, or "overlapping"  definitions/membership.

Groups and mailing lists are most often defined to make use of actual e-mail addresses: either directly as a list of e-mail addresses, or by  defining the membership to be users who each have a canonical e-mail  address. However, the MTA, via its new in MS 6.3    MTA  option (and whatever LDAP attribute    names), also  supports defining groups and mailing lists for which e-mail addresses  are constructed from other LDAP attributes that do not themselves  contain proper e-mail addresses.

Furthermore, as of MS 6.3 and its new    MTA option, it  is possible to define "meta-groups" and  "meta-lists": where a single meta-list definition provides  what amounts to an entire collection of definitions of different lists.

As of 7.0.5 and its new   mapping table,  it is possible  to use alternate LDAP attributes and values for group/list  authorization checks. In particular, this can be useful when dealing with group/list information stored in an LDAP directory using a  non-Oracle schema.

Now any time that a group or list with "large" membership of e-mail recipients is defined, and any time that a message is to be sent  to an especially "large" number of recipients, there are some  issues worth considering; these issues will each be discussed in  greater detail in sections below.



 Defining the actual list membership; see Defining_membership_of_large_lists. 

 Sensible error handling; see  Proper use of lists  rather than groups. 

 Restrictions on senders; see Restricting posting access to large lists. 

 Performance in submitting the message; see  Performance submitting mass mail messages. 

 Impact of this message (and possibly its multiple copies requiring   processing) on other message processing; see Addresses per message copy. 

 The appropriate choice of processing priority for the message. This may vary from "urgent" for messages that are time-critical, to  "non-urgent" for messages that while of general  interest are not time-critical and might be more efficiently  processed during "off hours". (Note that "importance" is a separate measurement than "processing  priority": messages can be time-critical but not very important,  as for instance a message that a party is about to start in the coffee  room, or important without being time-critical, as for instance a  message that system down-time is scheduled for two weeks away.) 

 The timing of attempting delivery of the message: for some   messages, it may be desirable to delay even attempting to    deliver the message until some pre-determined time. See SMTP SUBMIT FUTURERELEASE support. 

 Efficient storage of the messages; see Addresses per message copy. </li>

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See also:
 * Mailing lists
 * ldap_group_url1 MTA Option
 * ldap_group_url2 MTA Option
 * ldap_url_result_mapping MTA Option
 * process_substitutions MTA Option
 * GROUP_AUTH mapping table
 * Defining membership of large lists
 * Alias file LDAP URL alias values
 * Proper use of lists rather than groups
 * Restricting posting access to large lists
 * Performance submitting mass mail messages