Hi my name is***** am sorry to hear you are having this problem. This usually happens if a fax machine needs a new drum. The line is a sort of warning indicator for the part needing to be replaced. This would be on their machine though and not yours the part would be needed for. If this is happening to multiple people/machines let me know. If not please don't forget to leave a positive rating by clicking on the stars/smileys it is greatly appreciated. If you have any questions at all let me know.
That is actually why I asked if it was happening with multiple numbers. That would mean it is your machine. If you are making a copy with lines as well that is not good. When you print do you get lines? If you copy a blank sheet does it have lines?