Here is a list of frequently asked questions and answer:
Q: Why is there a 65 character filename limitation?
A: Because the filename must be stored in the subject line of each mail. Gmail only shows about 85 characters in the subject field. It allows GMail Drive to enumerate the files quickly - instead of having to read every single mail which would be very slow.
Q: Why is there a 20 Mb filesize limit?
A: Because Google imposes a 20 Mb mail attachment limit.
Q: I believe the Gmail attachment limit is > 20 Mb?
A: Yes, it appears that some Gmail servers accepts around 24 Mb. The official limit is still 20 Mb though.
Q: How do I prevent files/mails from being forwarded to my POP3 account?
A: The Use Draft Folder option in GMail Drive will put mails in the draft folder instead. This way, the mails generated will not be forwarded when you have the POP3 option enabled in Gmail.
Q: Can I use it from a USB memory stick?
A: Well, if you mean without installing the tool through the setup.exe, then No. Installation is required since GMail Drive needs to put information in the Windows System Registry.
Q: I cannot connect?
A: Please refer to the Problems with connecting topic. Also make sure to always have the latest version of the tool installed.
Q: How can I map a drive letter?
A: A Shell Namespace Extension does not have the ability to map a drive letter.
Q: Why doesn't my backup software work with the tool?
A: See answer about mapping a drive letter. Your software may be accessing files on your harddrive using old DOS style instead of the modern shell-style. Genuine Windows software, such as the Total Commander filemanager, works just fine with GMail Drive.
Q: How can I access GMail Drive from a command line?
A: I'm not familiar with any command line tool, but you can script it.
Q: Will you provide automatic splitting of files so it is possible to store files larger than 20 Mb?
A: No, I'm sure Google put the attachment size limit there for a reason.
Q: Will you create a drive for {name of webmail offering xxx Gb storage} too?
A: No. I have no plans to create drives for other webmail vendors.
Q: Can I have multiple drives?
A: GMail Drive only supports a single drive. You can experiment with turning off Auto-Login and create a Windows shortcut on the desktop with the following line (one line):
%windir%\explorer.exe /separate,::{20D04FE0-3AEA-1069-A2D8-08002B30309D}\::{2B3453E4-49DF-11D3-8229-0080BE509050}
Q: Does it work on Windows 64-bit?
A: GMail Drive installs an icon on the desktop that may work. You will not see it in the My Computer folder.
Q: Are my files safe?
A: When you use the "Use Secure HTTP"-option in GMail Drive, data is encrypted while being transferred on the internet. The mails themselves are not stored with encryption. Also I cannot guarantee that files can be accessed in the future if Google decides to block the tool.
Q: Can I have the source code, please?
A: The source code has not been released, but it might be some time in the future. If you want to study Shell Namespace Extensions you can find another sample, ADF View, on my website that includes GPL'd source code.