There is a webpage available to do this. Firstly, you must know:
- the name of the mailing list you are subscribed to (eg: cubs@sidneyscouts.com)
- the email address the you are currently subscribed with (eg: steve@minecraft.com)
- the password associated with your account (the system should send out monthly reminders of your password); if not, then you will have to reset your password first
Next, open a browser and type in the following URL:
http://sidneyscouts.com/mailman/options/mailinglist_name/email_address
Where:
mailinglist_name is the name of the mailing list with the @ replaced with an underscore "_"
email_address is your email address
For example:
http://sidneyscouts.com/mailman/options/cubs_sidneyscouts.com/steve@mine...
When you go to this page, it will ask you for your password. Enter it, and then you will be on a page where you can set options for your account. Enter your new email address at the New address: prompt, and again at the Again to confirm: prompt. Then click the Change My Address and Name button.
Note: if you check the Change globally option, it will change your email address for all lists that are associated with your old email address.