Subscriber List Definition

The Subscriber List wizard lets you define the settings of a subscriber list or edit an existing list.

Note: A subscriber list is only fully editable while it is "empty", meaning that there are no subscribers on the list. For a non-empty list, only certain settings are editable.

For a Hybrid Subscriber List (which augments the features of a standard subscriber list with the advanced features of a LISTSERV list, covering advanced use cases such as email discussions groups), the wizard has eight pages:

General, List Type, List Options, Posting Restrictions, Topics, Profile Fields, Profile Field Details, and Summary

The top row of the wizard displays links to these pages. The page that is currently open is highlighted. Depending on the choices made on some of the wizard pages, other pages may become disabled or may be shown in different versions. If a wizard page is disabled, then it means that this page is not necessary with the current choices and can safely be ignored.

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Posting Restrictions Page: Who May Post, Allowed Content & Size Limits

Note: This screen is disabled for a subscriber list in standard announcement mode and is not visible at all if the LISTSERV Maestro administrator has disabled Hybrid Subscriber Lists for the account or group.

The screen defines the general restrictions for postings to the LISTSERV list if the posting is made using a "standard submit" or is a posting from a subscriber (for discussion lists), depending on the list type. The following tabs may be available:

Standard:

• Allowed Sender Addresses
• Editors
• List Moderation (under Advanced for unmoderated-discussion-type list)
• Attachment Handling
• Size / Message Limits

Advanced:

• Posting Confirmation

To switch between the different tabs, select the name of the tab you want to go to from the drop-down menu in the tab header.

Allowed Sender Addresses

This tab is only available for announcement-type and unmoderated-discussion-type lists, where the tab also looks differently:

• Announcement-Type Lists: Specify the addresses that are allowed to post to this announcement list. Click the Edit link to specify the addresses that are allowed to post.
   
• Unmoderated-Discussion-Type Lists: Specify if you either want to allow everyone to post to the list, or if only subscribers and, optionally, a given list of non-subscribers are allowed to post. In the latter case, click the Edit link to specify the addresses that are, in addition to the subscribers, allowed to post.

Editors

This tab is only available for user-defined-type lists.

It lets you specify any addresses that are used as "Editors" for the list. Click the Edit link to specify the addresses that are supposed to be editors.

List Moderation

This tab is only available for the discussion-type and user-defined-type lists, not for announcement-type lists.

The List Moderation tab defines the moderation settings of a list. It is available in different version for different list types.

Note: For an unmoderated-discussion-type list, at first glance it seems illogical to have a List Moderation tab at all (after all, the list is unmoderated). However, there are actually some cases in which moderation may even be required on an unmoderated list. These cases are however advanced cases, which is why this tab appears in the "Advanced" group for unmoderated-discussion-type lists. For such lists, moderation is generally not used, however, individual subscribers (for example known "troublemakers") can be marked for moderation anyway, even when all other subscribers can post without moderation. Therefore, in some cases the moderation settings are needed even for unmoderated lists.

The following options are available on the different versions of this tab:

• Moderator Addresses: Specify the addresses to which list postings that require moderation are forwarded. Only after a moderator has reviewed and confirmed a list posting will it actually be distributed to the list. Click the Edit link to specify the addresses.
   
• Moderation Type: If there are several moderator addresses, then LISTSERV can either send a posting that requires moderation to only one of the moderators (LISTSERV selects which one) who must then approve the posting, or LISTSERV can send a copy of the posting to each moderator, and an approval from any of them will allow the posting to be distributed. Choose which type you want to use for this list.
  
  Note: This choice is disabled unless you have at least two moderator addresses specified (since the choice does not make much sense while there is only a single moderator).

In addition to the above options, there may be up to two more options:

For moderated-discussion-type lists, two more options are available but are usually hidden and are only displayed if you click on the Show advanced distribution handling options... link.

For unmoderated-discussion-type and user-defined-type lists, only one further option is available, which is however always visible.

The further options are:

• Moderator Approval of List Postings: (Available for both kinds of discussion-type lists and user-defined-type lists.)
  Select the mechanism by which a moderator must approve a posting that requires moderation:
  • A simple "OK" is enough: The moderator can approve postings by sending back an email to LISTSERV with "OK" as the only content, or the moderator can approve the posting via the LISTSERV Web Interface (if the web interface is installed).
  • Require the moderator to forward the full message: The moderator has to forward the whole message to the list in order to approve it (i.e. essentially the moderator re-posts the same message, which will then be distributed directly). Note that with this mechanism, an approval via the LISTSERV Web Interface is not possible.
  
  
• Unmoderated Senders: (Available only for moderated-discussion-type lists.)
  Specify any addresses that are allowed to post to the list without having to go through moderation (you do not have to specify any moderator addresses here, since moderators are always allowed to post without going through moderation themselves). Click the Edit link to specify the addresses.

List Moderation (for unmoderated-discussion-type or user-defined-type list)

This version of the List Moderation tab is available only for unmoderated-discussion-type lists (where it is a tab in the "advanced" section) and user-defined-type lists (where it is a tab in the "standard" section).

Defines the moderation settings of the list:

• Moderator Addresses: Specify the addresses to which list postings that require moderation are forwarded. Only after a moderator has reviewed and confirmed a list posting will it actually be distributed to the list. Click the Edit link to specify the addresses.
   
• Moderation Type: If there are several moderator addresses, then LISTSERV can either send a posting that requires moderation to only one of the moderators (LISTSERV selects which one) who must then approve the posting, or LISTSERV can send a copy of the posting to each moderator, and an approval from any of them will allow the posting to be distributed. Choose which type you want to use for this list.
  
  Note: This choice is disabled unless you have at least two moderator addresses specified (since the choice does not make much sense while there is only a single moderator).

To show additional advanced moderation settings, click on the Show advanced distribution handling options... link:

• Moderator Approval of List Postings: Select the mechanism by which a moderator must approve a posting that requires moderation:
  • A simple "OK" is enough: The moderator can approve postings by sending back an email to LISTSERV with "OK" as the only content, or the moderator can approve the posting via the LISTSERV Web Interface (if the web interface is installed).
  • Require the moderator to forward the full message: The moderate has to forward the whole message to the list in order to approve it (i.e. essentially the moderator re-posts the same message, which will then be distributed directly). Note that with this mechanism, an approval via the LISTSERV Web Interface is not possible.
  
  
• Unmoderated Senders: Specify any addresses that are allowed to post to the list without having to go through moderation (you do not have to specify any moderator addresses here, since moderators are always allowed to post without going through moderation themselves). Click the Edit link to specify the addresses.

Attachment Handling

Defines how attachments of postings are handled by the list.

In Standard Mode, there are only three different options:

• Remove all attachments from list postings: Any postings that include attachments are distributed but without the attachments.
   
• Reject postings that contain attachments (and notify the poster): Any postings that include attachments are rejected and not distributed. The poster is notified.
   
• Accept list postings even if they contain attachments: All postings are distributed, no matter if they contain attachments or not, and all attachments are preserved.

To enable the Advanced Mode, click on the Switch to Advanced Mode link. In advanced mode, there is another fourth option:

• Decide based on attachment type: Any postings that include attachments are inspected: If they contain only attachments of allowed types, they are distributed normally, with all attachments. If they contain (some) attachments of disallowed types, then either those disallowed attachments are removed or the whole posting is rejected (and the poster is notified about this).
  
  Check those attachment types (MIME-types) that you want to specify as allowed attachment types. If you need to specify an attachment type as allowed for which there is no checkbox, click on the Edit link and enter the MIME-type (or types) of those additionally allowed attachment types. Then, determine what shall happen if a posting contains any disallowed attachments (remove the disallowed attachments or reject the whole posting).

Also in the Advanced Mode, there are a few additional settings:

• Reject HTML-only messages and remove HTML part from multipart messages: If checked, then all postings that are only HTML will be rejected, and all multipart messages that contain HTML as one of their parts will be stripped of this HTML part.
   
• Remove non-MIME attachments (inline uuencoded attachments): If checked, then attachments of this special type will be removed from the posting before it is distributed.
   
• Remove Microsoft Exchange formatted attachments: If checked, then attachments of this special type will be removed from the posting before it is distributed.
   

Size / Message Limits

Defines size or message count limits for the list:

• Limit each message to: Allows you to specify how "large" any individual message may be at maximum. Either leave the field empty (which means that there is no limit), or specify a positive number as the limit and select what kind of limit this number describes from the drop-down menu.
   
• Daily limit for whole list: Allows you to specify that only so many postings may happen on this list on any given day. Leave empty for no limit or specify the maximum number of postings to the list per day, no matter who is the sender.
   
• Daily limit for each user: Allows you to specify that each user may only make so many postings to the list on any given day. Leave empty for no limit or specify the maximum number of postings to the list per day for each user (sender). This value must be less than or equal to the Maximum postings allowed per day for whole list (see above).

Posting Confirmation

To avoid spamming of a list and to verify the origin of a list posting, it is possible to enforce that postings to the list are confirmed by the poster before they are actually being distributed to the list.

Note: Postings sent with Maestro never require this additional confirmation and are therefore not affected by the settings made here. These settings apply only for manual postings.

The options are slightly different for the different list types:

• For moderated-discussion-type lists:
   
  • No confirmation required: Postings are accepted without an additional confirmation (unsecure!).
     
  • Require the moderator(s) to confirm their own messages: Normal posters do not have to confirm their postings, but moderators must confirm any posting they submit.
    
    The idea behind this is the following: On a moderated discussion list, all postings go through moderation anyway and thus any spam can easily be stopped by the moderator. So in theory, the only entry to the list would be spoofing the moderator addresses (since their postings do not go through moderation). Therefore, the requirement for moderators to confirm their own postings because anyone spoofing a moderator address would be unable to provide this confirmation so his postings would not be distributed.
    
    This is the minimum recommended settings for moderated lists. However, it still has a drawback because if a lot of spam is sent to the list, then even though this spam will not be distributed, it will still end up in the moderator's inbox, making life difficult.
     
  • Only require confirmation for postings from addresses that are not on the list: Posters that are subscribed to the list do not have to confirm their postings, any moderators or non-subscribers must confirm any posting they submit.
    
    The idea behind this is the following: The weakness of the previous option was that it had the potential of flooding the moderator's inbox with spam (since the only protection against spam would be the moderator himself). Under the assumption that most of this spam would originate from addresses that are not subscribed to the list themselves, this option here offers an improvement: Any list subscribers are still not required to confirm their postings (which will then be sent to the moderator for approval), but all non-subscribers will first have to confirm their postings before they are even forwarded to the moderator, and since this usually not happens for spam, the spam does not even reach the moderator's inbox.
     
  • All messages require confirmation: All postings are only distributed to the list once they have been confirmed with LISTSERV's "OK" mechanism (see below for details).
     
• For all other list types:
   
  • No confirmation required: Postings are accepted without an additional confirmation (unsecure!).
     
  • Postings must be confirmed with an "OK": Postings are only distributed to the list once they have been confirmed with LISTSERV's "OK" mechanism (see below for details).

About LISTSERV's "OK" mechanism for confirmations: To confirm a posting, LISTSERV sends an email back to the poster requiring the confirmation. The poster must then respond to this confirmation request by either sending an email with "OK" in the body back to LISTSERV, or by clicking on the confirmation link provided in the email (the confirmation link is however only provided if the LISTSERV Web Interface is installed on the LISTSERV server).