And does it work? I mean, even if I request deletion on server, messages stays on server unchanged.

Hmm ... I thought it did work , but I can't swear to it . I'll just get the machine and try it . One Mo .

Well , I've tried it , and you are right ! Not only that but the dialog that appears asking if you want to delete from the device only , or server and device , only seems to be shown on unread emails . Read ones seem not to check for confirmation .

I will have to look at the settings on the GoogleMail site , I think that there may be some adjustments which determine what Google should do with downloaded/read mail . I am sure I set mine to keep all mail , perhaps some finetuning of this will have the effect you desire .