how to remove \n from file?

[bowlofred]

If you remove the newline, they won't be separate lines.

I suspect the error is telling you that you have whitespace at the beginning of the lines. For getmail, the configuration assumes that if it starts with whitespace it is a continuation of the previous line.

A parameter value, if necessary, can span multiple lines. To indicate that the second and subsequent lines form a continuation of the previous line, they need to begin with leading whitespace, like this:

first_parameter = value
    first parameter value continues here
second_parameter = value

Get rid of the leading whitespace.