When I receive an email attachment with a file name that includes nn-nn Apple Mail (or MacOs) converts the nn-nn to nn/nn, making the file unreadable in Windows. Example: example 15-20.pdf becomes example 15/20.pdf
How can I prevent this behavior?
MacBook Pro 15″, macOS 10.15
When I send myself a file with a - in the name, it doesn't get converted.
Maybe the email server is doing that, but I don't know why.
Select a message with the renamed attachment in Mail, then View menu > Message > Raw Source.
Scroll down and look at the filename and name of the Attachment. If it has a slash in it there, that would have been done by the sender's email client or server.
I can't imagine Mail doing that as it is an invalid file name character.
Very interesting. Raw Source shows the original character to be ":"
Looks like Apple Mail converts the ":" to a "/"
Windows converts the ":" to a "-"
: is not a valid/allowable character in a filename.
Typically not valid
> (greater than)
: (colon)
" (double quote)
/ (forward slash)
\ (backslash)
| (vertical bar or pipe)
? (question mark)
* (asterisk)
< (less than)
As Bob noted, : is not allowable due to the history of the Macintosh OS. The colon was a folder separator for System X (pre OS X). It likely assumed it was a folder separator and converted it to the current folder separator.
mail attachment file name change
