Exchange randomly rejecting IMAP authentication

Posted on 2008-10-20
Medium Priority
Last Modified: 2013-11-29
Our exchange server has developed an issue in recent weeks where it will randomly kick back a prompt that the entered password is incorrect. This is happening both with computers on the local network, and remote access. No configuration changes have been made to the server, and the server is functioning as most of the time just re-entering the password allows it to authenticate and retrieve mail.

I am wondering if there is some kind of time-out setting in Exchange that might be returning an incorect password message too quickly. I have been monitoring the server and the system load, both CPU and network wise, is pretty minimal. The password request comes up at random intervals, sometimes 15 minutes apart, sometimes a couple hours. Nothing obvious is jumping out at me as to what might be the cause.
Question by:ArthroWaveIT
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
LVL 31

Expert Comment

ID: 22761957
There is a Time Out setting for IMAP in Outlook which it looks like might need lengthening.  This is in the Advanced settings.

Author Comment

ID: 22769470
I have tried adjusting the time out setting in outlook, and it does seem to make the authentication rejected popups less frequent, however this does not really solve the issue. Something in Exchange is not responding properly. I am wondering what might be causing the rejection itself from Exchange, since the password is correct and the account is active. The email clients are checking mail every 5 mintues or so, and most of the time it works fine. The server is not over used and the network bandwith being used by the server is generally quite low. This is happening on the local network, so network latency seems unlikey.
LVL 31

Expert Comment

ID: 22769554
You don't have accounts where there are thousands of emails in the IMAP folders?  If these headers are pulled down from the server regularly enough the Client could be processing the last request when a fresh request is issued.

Author Comment

ID: 22769764
While some of our accounts do have a lot of messages in them, this issue still occurs on accounts with less than 100 messages in their mailbox, and a relatively small mailbox size. Also, the issue just started happening a couple weeks ago, and the larger mailboxes have been large for quite some time before that, with nothing in the configuration or setup being changed. Your comment makes sense as a possibilty, but I am still missing something that has caused this issue to manifest recently.
LVL 31

Accepted Solution

moorhouselondon earned 600 total points
ID: 22770348
Is this happening to particular users on a random basis, or is it always the same users?

Time to get Wireshark involved maybe?  First of all just filter IMAP traffic into and out of the server - do you have a Switch that has a port that can be used as a monitor?  Start Wireshark capturing, then halt it when anyone gets a password prompt.  There will be a lot of traffic but it can be further filtered to test various hypotheses.

Featured Post

Office 365 Training for IT Pros

Learn how to provision tenants, synchronize on-premise Active Directory, implement Single Sign-On, customize Office deployment, and protect your organization with eDiscovery and DLP policies.  Only from Platform Scholar.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article will help to fix the below error for MS Exchange server 2010 I. Out Of office not working II. Certificate error "name on the security certificate is invalid or does not match the name of the site" III. Make Internal URLs and External…
New style of hardware planning for Microsoft Exchange server.
Many of my clients call in with monstrous Gmail overloading issues with Outlook. A quick tip is to turn off the All Mail and Important folders from synching. Here is a quick video I made to show you how to turn off these and other folders in Gmail s…
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…
Suggested Courses

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question