Platforms

Non-z/VM


Abstract

Provided for DBMS lists with UEMAIL fields to work around RFC821 requirement that an email address local-part must be evaluated case-sensitively.


Examples

z/VM:

(not supported)

Unix:

IGNORE_EMAIL_CASE=0

export IGNORE_EMAIL_CASE

Windows:

IGNORE_EMAIL_CASE=0


Details

IGNORE_EMAIL_CASE=0 (the default) tells LISTSERV to operate per RFC821 and treat address fields with differently-cased local parts as different addresses.  

IGNORE_EMAIL_CASE=1 causes the ADD command to ignore the case of the "local part" of list subscriber entries (that is, the part of the address that is to the left of the "@" sign). Although most modern mail clients are configured to ignore the case of the local-part, this behavior technically violates RFC821 which states that local-parts are considered case-sensitive.

If an entry whose "local part" differs only in case is found in the list during an ADD operation (for instance, JOE@EXAMPLE.COM vs. joe@EXAMPLE.COM), that entry will be assumed to be the entry that was sought, and the address field will be updated to the new case (that is, "JOE@" will be changed to "joe@").  No other change will be made to the entry unless there is a change in the name field, in which case the name field will also be updated.

If there is no change in the address field associated with the entry, no change will be made to the entry (again, unless the name field changes, in which case the entry will be updated).  

In either case, when this option is set, a new entry with a different case will NOT be added.

Note the following caveats:

        1. Pre-existing duplicates are not automatically removed from lists when this option is set.
        2. Because ADD updates the case of entries, it is possible to end up with multiple entries that have exactly the same case.
        3. The only real way to de-dupe a given address is to DELETE and then re-ADD it.

Other than this, existing duplicate entries work exactly as they did before the option was enabled.  Commands that do not add new entries ignore the option.

And finally, it should be carefully noted that the PUT command also ignores the option.