EXAMINE Mailbox not selectable

Error​​

Error: EXAMINE Mailbox not selectable

Cause

This error indicates that your IMAP server is not RFC-compliant and is not allowing us to open a specific folder (even though the folder was advertised as accessible). As per RFC specifications, an IMAP system should identify folders that are not selectable using the "NoSelect" flag. It is therefore invalid for an IMAP system to omit this flag but later return this error.

Resolution

We recommend the following:

1. Check to see if the folder can be accessed by connecting an IMAP client (Outlook, Thunderbird, etc.).
2. Consider filtering the offending folder. The folder will be skipped during migration.
3. Check to see if the offending folder is exposed to IMAP. This is particularly relevant to Gmail and G Suite mailboxes.
4. If the error is with the Destination (not the Source), consider disabling duplicate detection:
   1. Edit your mailbox or connector.
   2. Reveal Advanced Options.
   3. Checkmark the option Do not search Destination for duplicates.
   4. Resubmit your mailbox for migration.
5. Consider forcing the use of the SELECT command (instead of the EXAMINE command):
   1. Edit your mailbox or connector.
   2. ​Reveal Advanced Options.
   3. In the Support Only options, set a value of MustUseSelect=1.
   4. Resubmit your mailbox for migration.