There's a few simple things that could be done in game to improve notifications.

First up there is allready a mailbox in game, so why i it not used for messages, such as..."server will go down for maintenace on ...", Would kinda make sence, would it not? and no, i do not mean the messages one hour prior to it, how about 24h warning in mail. at least for me, i come to forums less than once a week so aint gonna see the warnings on shutdown here.

And as it is MAILbox, why the heck sending mail via it costs balens? bit stupid i'd say. As it stands now guilds need to make a new page/forum/use raidcalls/so on. Just to get info to others on guild. Why, whats the point?
Heck just ad the possibility to mail (in game) to all in guild on uppcoming stuff to do together, merges...
And make it free. It is a social game so a workin mailsystem will enhance that side of it.