The software managing the list will answer with a message containing a text along these lines:
To confirm that you would like email@example.com added to this mailing list, please send an empty reply to this address: firstname.lastname@example.org Your mailer should have a Reply feature that uses this address automatically. This confirmation serves two purposes. First, it verifies that I am able to get mail through to you. Second, it protects you in case someone forges a subscription request in your name.To confirm your subscription, you should answer with an E-mail (again, its content is unimportant) to the given address. In the example above, it is email@example.com, but the 950281983 and mgoifceebaalgongomon parts will be different in each particular case. This makes forged subscriptions virtually impossible.
The software tries to determine your E-mail address and tells you what it think it is (it would be firstname.lastname@example.org in the above example). It may happen that you would like to use another address (e.g. because it is your physical address email@example.com and not your logical address firstname.lastname@example.org). You can do it by changing the @ sign to a = sign in the address you would like to use and putting this before the @ sign of the subscription address. As an example, to use the address email@example.com, you would send a message to:
In case you subscribed with an explicit address (e.g. firstname.lastname@example.org), you would use instead:
Just as in the subscription procedure, you will receive an answer requesting that you confirm your wish to unsubscribe by sending a message to a a complicated address. The purpose of this is again to avoid being removed from the mailing-list by a malicious person.