Problem viewing included pictures [SOLVED]

Hi there!

Since about 2 weeks i have a problem viewing pictures in html-mails:

When i view the message in Thunderbird (Linux and Win 11), there is only a placeholder for the picture.

When i view this message in my Roundcube webmailer, all is fine an the picture is shown immediately.

At the moment i have no idea what’s going wrong, but because my users have the same problem it’s not so funny!

I really hope someone has an idea to solve this!

Thanks in advance,


This is the view in Roundcube:

Here all is absolutely fine!

@Mike_S If you view the html source of the email in Thunderbird does the src attribute of the img element look correct?

Hi duncanc!

I hope this is the right thing:

<img src=3D"cid:40babc34a61ec99ba331f990ecb43836" title=3D=
“powered by phpList version 3.6.8, © phpList ltd” alt=3D"powered by ph=
pList 3.6.8, © phpList ltd" border=3D"0" />

And short after this follows:

Content-Type: image/png; name=powerphplist.png
Content-Transfer-Encoding: base64
Content-ID: <40babc34a61ec99ba331f990ecb43836>
Content-Disposition: inline; filename=powerphplist.png


and much more…

So i think, that the original picture is included via base64?!

@Mike_S That is the “powered by phplist” image. Look for the image that you included in the email. It should appear earlier in the source of the email.

Ok, pls have a look at the source of the mail:


@Mike_S This is the image in the email

If I try to display that in Firefox or Chrome it is rejected because the server’s certificate expired on 15 June, which probably explains why the problem has been happening for a few weeks.

You need to raise this problem with the system administrators, who need to renew the certificate.

Hi duncanc!

Thanks! This was the right hint!

My let’s encrypt certificate has expired and after renewing it all is fine!

You make me happy :wink: