I configured the System > Mail Service some time ago and send a test mail occasionally just to check.
Now I configured WIO ( Who Is Online? ) to send mails when it tracks events, it works, all is well.
However, both the WIO mails and the Test mails come marked as having attachments, yet there is no attachment… nor should there be.
In the case of the WIO mails, I did not configure that to send any collected mail, only single text.
Any explanation for this?
I just ran a test mail run and also turned on the emails for one of my clients on WIO and I found the same effect of having a paper clip symbol indicating an attachment. My mail client is Thunderbird.
Interestingly, I have also found that a communication I received from the sudo development people announcing a new release of the sudo package also showed an attachment when it didn’t have one.
In all the above cases, once I had opened the mail messages to read them the paper clip symbol was gone and never came back.
Not all mail messages I get have the paper clip symbol but it is not just the mails from my IPFire system that show this effect.
Unfortunately I have no idea why this is occurring.
FYI the screenshot is from a webmail client called Roundcube. Opening the e-mails in a separate or maximised window do not remove the paper clip.
Slightly annoying… 
I have Roundcube as well so I also tested that out and can confirm what you are finding.
If I open the message in Roundcube the attachment icon stays in place. Also for the mail announcement from the sudo development people.
If I then go and look in Thunderbird the message shows that it has been read but the attachment icon is still in place. If I then open the message in Thunderbird the icon disappears and if I then look in Roundcube the message shows with the attachment icon.
So Roundcube and Thunderbird show the attachment icon in some cases where there is no attachment but clearly deal with it differently.
Did some searching and there are a lot of mails about Outlook having that problem. The majority of issues with Thunderbird that I found were people complaining that they has sent attachments but they weren’t received.
There was one topic I found with Thunderbird where the person had not sent an attachment but the icon showed on their system. That issue was tracked down to a business card image in the signature.
I don’t believe that the issue we are experiencing is related to an embedded image in a signature but I am not certain.
I suspect there must be a problem with the clients receiving the emails. They are identifying an attachment when one is not there.
I checked the source of the various emails.
I have a separate email with a signature image and in the source it has the following line:-
Content-Type: application/gif
MIME-Version: 1.0
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=“Signature.gif”
Checking the source of the IPFire Test Email there is no message about attachment at all. The following is the only message regarding the dispostion of the content.
Content-Disposition: inline
Content-Length: 29
Content-Transfer-Encoding: binary
Content-Type: text/plain
Which indicates that the message had text/plain content and no attachment.
I have also found that many, but not all of the announcement messages from the Bacula project also show the attachment icon in Roundcube. None of them have an attachment.
This seems to be a generic problem with mails from many sources but not consistently.
As the sources of those messages do not flag up any attachment this indicates to me that the problem is with the involved clients - Thunderbird and Roundcube.
The mails that show the icon have
Content-Type: multipart/mixed
The mails that don’t show the icon have
Content-Type: multipart/alternative
Looking up these two content types the multipart/mixed, according to the RFC, is intended for use when the body parts are independent and intended to be displayed serially. This includes when attachments are to be sent but doesn’t have to include attachments.
It looks like Thunderbird and Roundcube are presuming that if multipart/mixed has been used then an attachment must have been applied, even if it hasn’t and when Thunderbird opens the mail and finds that no attachment is present it then ignores the multipart/mixed and knows to remove the icon but Roundcube stays always based on the multipart/mixed line in the email source.
My Android client doesn’t show an attachment icon for the IPFire Test Email.
Since you mentioned Android I can do no less than checking that as well.
I use Aqua Mail (have for many years) and it does not show attachment.
Patches have been submitted to fix this for the test email and for the wio emails.
@bonnietwin , thanks for the patch.
BTW, it shows the origin of the problem. There is an attachment commented out for the test mail.
The mail head of WIO seems such to be a copy of the original test mail head.
