Asking for the credentials of the domain Im emailing

[sudo]

Im having a weird issue.
A customer of mine is trying to respond to an email. When he attempts this he gets a pop up window that asks for the credentials (un and pw) of the domain he is trying to email. The first message asks for the username and password of the mail server he is emailing. If you enter bad creds or hit cancel a new window pops up. The second one says "A username and password is being requested by email.domain.com. They site says: "email.domain.com" Where email.domain.com is the MX of their mail server.
So it looks like its their email server asking for the creds, but why? I sent a test email from an exchange server and it went through with no issues.
My customer says this is the only time this issue has happened.
Any Suggestions? Im new to Zimbra and at a loss on what might be causing this.

[MightyGorilla]

I've been trying to find an answer to this as well. It seemingly starts happening at random with one of our users.
In our case, our message is only slightly different, *...The site says: "Zimbra"*

If the user enters their credentials for our Zimbra server, the message seems to go away for a time, but will come back if they close out ZD and reopen.

[mapoftampa]

We're having the same issue. I thought it was tied to Zimbra Desktop at the application level, but it's happening on the web client too. Has anyone made it past this issue?

Thanks,
Michael

[tonster]

Are they responding to a message from that other customer? It could be that there is an image in the message that is in the users briefcase. There was a bug earlier where images in signatures were not being stored properly, and it was prompting for authentication to display the image.

[yvespires]

Are they responding to a message from that other customer? It could be that there is an image in the message that is in the users briefcase. There was a bug earlier where images in signatures were not being stored properly, and it was prompting for authentication to display the image.

i have this problem

https://mx.domain.com.br/home/user@doma ... nature.png

image is store inside briefcase, everytime i try to send new email it asks for credentials

any solution?

zimbra version: Release 8.0.4.GA.5737.UBUNTU12.64 UBUNTU12_64 FOSS edition.

[phoenix]

The current version of ZCS is 8.7.7 and your version is old, I'd suggest you upgrade to the most recent release and see if that fixes the problem. You could always install it in a test environment if you don't want to upgrade your live server immediately.