LISTSERV - LSTSRV-L Archives - COMMUNITY.EMAILOGY.COM

On May 14, 2015, at 4:01 PM, F J Kelley <[log in to unmask]> wrote:

Hi Folks,
I've had a question on this and don't see any issue in the mail being sent or in the list configuration. So, obviously, I'm overlooking something.

A list subscriber asked why her post had been rejected:

Your posting to the LIST-L list has been rejected because it contains an
attachment of type 'IMAGE/GIF'. The LIST-L list has been configured to reject
such attachments. Please contact the list owner at
[log in to unmask] for more information.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please visit http://www.symanteccloud.com

There is of course, no attachment. I have had her cc me and there is nothing (not even a logo in the .sig). There is a warning:

To help protect your privacy, some content in this message has been blocked. To re-enable the blocked features, click here.

This happens only on replies. An original post to the list has no problems. Checking the mail headers of the rejected reply, I did see
Content-Type: multipart/related

But, as mentioned, no image file.

Would appreciate any thoughts on this. Thanks,
—Joe

The message apparently does contain an attachment of type image/gif. The image may be small, or the same color as the message’s background, or might be invisible for some other reason.

To verify this, you can go under ‘Server Administration’ to ‘LISTSERV Command’ and issue a

debug flags +keep_jobfiles

command, then have the subscriber attempt to post one of the affected messages again. While the debugging option is enabled, LISTSERV will keep copies of messages it receives in .deleted files in its spool directory. You can then view the contents of these files using the ‘jobview’ command-line executable that’s also in that directory. Once you’ve captured the message, you can tell LISTSERV to stop doing this by issuing a

debug flags -keep_jobfiles

Viewing this message should show you that the message is multipart/related, with (minimally) an HTML part and an image/gif part.

As far as how the subscriber can prevent this from happening, it depends on where the image is being inserted from and why. Making sure that the messages that he or she sends are plaintext might help. I’m also wondering if the image might have been accidentally included in the .signature set up in his or her email program, but that’s complete speculation.