No delimiter defiend when no mails

[Schluggi]

If one of the mailboxes has no mails, pymap-copy can't determine the delimiter and the tool will crash.

This will be fixed with #17.

[donvito-pl]

Hi. When trying to migrate mailbox (full of e-mails) I get this:
Python 3.7.3

Traceback (most recent call last):
File "pymap-copy.py", line 446, in
df_name = sf_name.replace(source_delimiter, destination_delimiter)
TypeError: replace() argument 2 must be str, not None

--destination-root into non-existing folder seems to cause the problem.

[Schluggi]

You can try to predefine the destination delimiter in line 154. If the delimiter is None the script will look at the first folder and grap that delimiter. Without an existing destination root it will stay None and the error eccurs.

I'll fix it in the future but in your case line 154 will fix it for now.

[donvito-pl]

Changing line 154, as suggested, solved the problem

destination_delimiter, source_delimiter = ".", "."