The first line of the note turns out to be longer than the width of the column
I tried to separate the fax and the email in different lines (as below) by putting tel and fax in different \mbox and using "\\" in-between but it rather generates a number of errors.
I can't really figure out what you are doing. A minimal working example (MWE) would clarify your situation. Perhaps the footmisc package can be helpful in this issue.
Is that what you are looking for? The hang option causes the hanging indent. Just play with the \footnotemargin to get the spacing you desire. Also in footnotes use \newline not \\ to break. It works here but not with \footnote{}. You will also need to watch the counter when you use footnotes in the paper elsewhere