Pos na kanete activate to voice mail.

Thanks to NickRock for the info.

Sto iphone epilekste phone-> Keypad-> grapste: *5005*86*123# patiste call

To 123 einai o kodikos tis cyta gia to phonokivotio. Den kserw gia thn mtn h alles etairies. Autos o kodikos isxiei gia oles tis xwres me monh diafora to 123 o opoios einai o kodikos pou yparxei prin ton arithmo tou fwnitikou kibotiou. 12399XXXXXX