#!/bin/cat
$Id: FAQ.Authentication_failure.txt,v 1.5 2017/09/04 11:03:57 gilles Exp gilles $

This documentation is also at http://imapsync.lamiral.info/#doc

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              Imapsync authentication issues
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Host1 failure: Error login on [imap.example.com] with user [foo] auth [LOGIN]: 2 NO [AUTHENTICATIONFAILED] Authentication failed


One over four imapsync syncs ends up quickly with the error message 
"Authentication failed" or "NO LOGIN failed" or similar. 
Authentication failure is the primary failure with imapsync
and since nothing tangible can be done without authentication, 
this stage must succeed to go further.

Here are some advices to get you pass this difficult stage of authentication:

  * Triple check each credendial parameter, there are three parameters at each side:
     * triple check --host1
     * triple check --user1
     * triple check --password1
     * triple check --host2
     * triple check --user2
     * triple check --password2

   * If you can authenticate successfully with an other imap client software 
     like Thunderbird or Outlook or Sparrow then it is a very good sign to 
     authenticate successfully with imapsync. Examine the parameters of 
     this other imap client and copy them as is for imapsync.

   * Use option --showpasswords
     At the beginning of the output, imapsync dumps all its command
     line parameters; it's the line after "Command line used:".
     With --showpasswords, imapsync prints the passwords received 
     instead of the string MASKED. It helps for debugging quoting issues.
     Option --showpasswords shows passwords again when the IMAP dialog
     is dumped by --debugimap option. Search for a line like 
     "Sending: 2 LOGIN test1 secret1" (secret1 is the password here)
     
     
   * It is sometimes very hard to quote correctly unusual characters,
     especially on Windows. See 
     https://imapsync.lamiral.info/FAQ.d/FAQ.Passwords_on_Windows.txt
     https://imapsync.lamiral.info/FAQ.d/FAQ.Passwords_on_Unix.txt
     The quicker trick might be to change the password temporarilly
     with easy characters like the classical alphabet, a long
     string will still ensure strong security.