> Hi. I've always thought that the listserv software didn't make
> distinctions between upper and lower case characters in an email
> address, but I just found today that someone had subscribed to the list
> twice once in all CAPS and then again with the same address in lowercase
> letters. They both stuck and now suddenly she has started to complain
> about receiving dupes.
>
> [log in to unmask] Subscribed on 10 Oct 1998
> [log in to unmask] Subscribed on 22 Oct 1998
>
> SO ... is the software case sensitive? Or is this just a fluke that got
> through when nobody was looking? And it it was a fluke will deleting one
> delete both?

In email addresses, the left side is case sensitive, but the right side
is not.  This is per Internet Mail standards.  LISTSERV observes this
case sensitivity when adding subscribers, but does a case insensitive
match when deleting them.