[Serusers] change in mailing list management

[Pavel Kasparek]

Hello all,

since now it is possible to use only web interface to manage mailing 
lists hosted on lists.iptel.org server. We had to disable the email 
commands interface as part of fight against spam (it was causing too 
many messages being sent from us, recognized by some blacklists as spam).

This means that for all actions like subscribing, un-subscribing, 
changing your preferences etc. you have to use the web interface. You 
can find a link to it at end of every message sent to the mailing list.

Sorry if it causes any inconvenience to you.

Pavel Kasparek