You've guessed it already! To unsubscribe from ‘email@example.com’ just send a message to ‘firstname.lastname@example.org’, then reply to the confirmation request. ezmlm will send you a message to let you know that you are no longer a subscriber. ezmlm will also let you know if the address was not in the subscriber list. If so, you are probably subscribed under another address. When this happens, construct an unsubscribe request that contains your subscription address.
If you message contains a ‘List-Unsubscribe:’ header, just click on it if your mail reader supports it and send of that message. If you mail reader doesn't support this, copy the entire address from after ‘mailto:’ until just before ‘>’, paste it into the ‘To:’ field of a new message and press “SEND”. Reply to the confirmation request.
Otherwise, you have to know your subscription address. To find it, look at the very first header of any message from the list. This should contain something like ‘email@example.com’ which tells you that the message number is ‘2345’ and the subscriber address is ‘firstname.lastname@example.org’. Now you remember that you subscribed a address, and construct the appropriate command address to remove that address from the subscriber database: ‘email@example.com’. (You can see that this is a normal unsubscribe request, with a ‘-’ followed by your subscription address with the ‘@’ replaced by a ‘=’. If you like, you can just use the address in the ‘Return-Path’ header, and replace the ‘return-2345’ with ‘unsubscribe’.) Replying to the confirmation request will return the desired acknowledgement that the address has been removed from the subscriber database.
You can also send -unsubscribe requests for each potential subscription address and reply to the confirmation requests. The message sent by ezmlm in response to you -unsubscribe confirmations will tell you if you -unsubscribe attempt was successful.
With ezmlm-idx(*) you can also send mail to ‘firstname.lastname@example.org’, ‘email@example.com’, and so on. For each message, the address will receive a reply telling you whether or not the address is subscribed or not. Construct a -unsubscribe message from the one that gave you a positive reply and you're off the list!
If you for some reason are not successful with these attempts you can as a last resort contact ‘firstname.lastname@example.org’. Please describe your problem and include a FORWARDED message from the list and a list of the possible addresses you might be subscribed under. The list owner will be able to help you get off the list, and can usually figure out your subscription address from the information sent (see Helping Users Unsubscribe).
Unsubscribe from subscription moderated lists works the same way as for normal lists. You never need approval to remove your address from a moderated list.
When a list is set up to allow posts from subscribers only(*), a post from an address (‘email@example.com’) may be rejected since this address is not a subscriber (even though mail to the subscriber ‘firstname.lastname@example.org’ reaches you, ezmlm has no way of knowing this). The easiest way to deal with this is to unsubscribe ‘email@example.com’ and subscribe ‘firstname.lastname@example.org’. If this is not possible/desirable, send the addresses in question with a note to ‘email@example.com’. The list owner can add your sender address (in this case ‘firstname.lastname@example.org’) to an extra address lists of non-subscribers allowed to post (and access the archive). The extra addresses are kept in a database much like subscriber addresses. In fact, you can add the address ‘email@example.com’ as an alias for the list ‘firstname.lastname@example.org’ by mailing ‘email@example.com’ and replying to the confirmation request. Again, you're changing the “target” address of the request from the default (the sender address) by adding the target to the command with the ‘@’ replaced by ‘=’. Of course, the “allow” list doesn't send out posts. It is solely a vehicle for storing “allowed” aliases.