Error
[ALREADYEXISTS]
Cause
This error indicates that your IMAP server is not RFC-compliant and gets confused about folder names because of "silent" renaming. It can also mean that a user disabled IMAP access to a folder at the Destination. This error message can come with different error messages ("mailbox" in IMAP terminology actually means "folder"):
- "Duplicate folder name"
- "Folder name conflicts with existing folder name"
- "Mailbox exists"
Here are a few cases illustrating the problem.
Case 1
- The Source has two folders, F1 and F2, with similar names (for example, foo-bar and foobar).
- We create folder F1 at the Destination (foo-bar).
- The Destination creates F1 slightly differently (for example, special characters are replaced, so foo-bar gets created as foobar).
- We create folder F2 at the Destination (foobar).
- This conflicts with F1, which was created as foobar (even though it was foo-bar), and the Destination says the "mailbox already exists".
Case 2
- The Source has a folder F1 (foo-bar).
- We create a folder F1 at the Destination (foo-bar).
- The Destination creates F1 slightly differently (for example, special characters are replaced, so foo-bar gets created as foobar).
- Later, you perform a Delta Migration pass.
- We find that folder F1 is not presented at the Destination (there is no foo-bar, only foobar).
- We try to create folder F1 again, and the Destination says the "mailbox already exists".
Case 3
- The Source has a folder F1 (for example, blah).
- We create a folder F1 at the Destination (for example, blah).
- The user disables IMAP access at the Destination.
- Later, you perform a Delta Migration pass.
- We find that folder F1 is not presented at the Destination (there is no blah).
- We try to create folder F1 again, and the Destination says the "mailbox already exists".
Resolution
We recommend the following.
- Check if the folder has a double space in its path (a Google IMAP bug will cause an error to be returned for this type of folder).
- Review if there are two Source folders with similar names.
- Check if the offending folder has special characters.
- Review if the Destination folder is an altered version of the Source folder (for example, special characters replaced).
- Check if the folder has been disabled for IMAP access at the Destination.
- Rename folders at the Source to avoid special characters, double spaces, and conflicts.