Command: subscribe/unsubscribe - staying in contact with Nemesis

Description:
	Nemesis offers some mailing lists. These are our lists:

	     nemesis@nemesis.de    for all interested in Nemesis.
	     events@nemesis.de     for planning RL events like the VCFe.
	     wizards@nemesis.de    for Nemesis' wizards only.

	Before you can 'subscribe' (and hopefully not 'unsubscribe' later)
	to the lists in every post office in Nemesis (also in the Nemesis
	Information Centre east of the church or in the Adventurers' Guild),
	you have to validate your email address stored in Nemesis - see
	also 'help mailaddr'. This is our "Double opt-in" (DOI) - see
	https://en.wikipedia.org/wiki/Opt-in_email .

	'subscribe' without argument shows the available mailing lists
	and which you have subscribed to with which email address.

	Wizards don't have to go to a post office, the Information Centre
	or the Adventurers' Guild. They can subscribe everywhere.

Syntax:
	subscribe
	subscribe <list>
	unsubscribe <list>

Examples:
	subscribe nemesis
	subscribe nemesis@nemesis.de
	unsubscribe nemesis
	unsubscribe nemesis@nemesis.de

Note:
	When subscribing (or unsubscribing) to the mailing list you can
	name the list by its complete mail address, e.g. "nemesis@nemesis.de"
	or by the local part "nemesis".

	If you change your address stored in Nemesis via 'set mailaddr'
	(and validate it), the mail addresses subscribed to mailing lists
	are NOT changed. Simply type 'subscribe <list>' to re-subscribe
	with your new mail address.
	No, this is not a bug! It IS a feature: There are lots of people
	who prefer to subscribe to mailing lists with different addresses,
	different to their "normal" email address. After setting (and
	validating) an address it is used with 'subscribe <list>' and this
	mail address is stored in the <list> - separately from your personal
	data. This way it is possible to subscribe to each mailing list
	with another mail address.

	BUT: Keep in mind that the Nemesis mailing lists are closed lists:
	Only subscribed addresses are allowed to post on the list!

	Although these mailing lists are managed from within Nemesis and
	therefore the subscribed mail addresses are stored in the MudLib,
	the addresses are kept away from all players and wizards except
	Archwizards (see 'help admin').

	VCFe: Vintage Computer Festival Europa - see https://vcfe.org/ and
	https://nemesis.de/pics/vcfe16/ .

See also: helpdir/mailaddr, helpdir/set, helpdir/admin