My browser ate my longer version post, so i try to keep it short

Simply, you are wrong.
It would be as ooc as is guildchat, it does serve a purpose. It is not completly OOC.
I thought i won\'t give any additionaly arguments because, above posts lack them in some sense as well ;>
Anyway, try to look at it from difefrent side. Treat offline messages as letters.
Maybe make delay of 15min before the \"letter\" is delivered, to keep it closer to letter form as it obviously isn\'t supposed to be e-mail^^
Another thing what is ooc is players not playing all the time, or at least most of it, what very often cause their chars to be rarely where hey should be and talk most of the time, like we are in real world.
So, two players who are rarely online and additionally are in very different time zones should have possiblity to send post to eachother where they can explain all this what they would talking.
Now you will say that it is why guilds have forums, there is IRC, e-mailing and so on. All this exist and thats why it should be put in game, especally for all the people who aren\'t used to forums/IRC and gving e-mail to a stranger.
Being guild leader i have receiced some PM\'s or mails, all in IC style. I would like them to be delivered in even more RP style, through Planeshift.
Can\'t you think a bit before writing somethink so wrong as you did in above posts? I\'m waiting for arguments.