As this is generally a long time problem (at least for me), there must be information discussed already, but the search didn't work for me. I apologize for the repetition.

On forwarded emails, attachments (temp files?) are created and sent along with the forward. I just accepted that and no one has mentioned it for years.

But on a recent forward to a Gmail address, the recipient reported that one of the attachments was a copy of a previous email I forwarded him. Is there a way of preventing this from happening?

Using 4.80.1028 and Pegasus for Windows user since 1996.

Well, I have an idea about what might be involved, but since all temporary files created are created with (more or less) uniquely hashed filenames it's hard to believe that this can happen at all, and without any reliable way for duplicating it it's almost impossible to figure out. Assuming it (only?) affects HTML text I took a quick look at my code to check whether I'm correctly initializing (= clearing) all filenames involved (and which I'm actually supposed to deal with) I didn't see any possibly involved part of my code, but again: Without knowing any kind of scenario making it happen it's very unlikely to be detected at all.

So as a workaround you're currently only left with checking your forwards for the topmost plain text and HTML parts on the attachments pane and delete them manually before hitting the Send button: It would not affect any HTML being forwarded if supposed to be included per the forwarding options - just don't deleted any pictures which it might contain. I'll get back to you if I can figure out anything else. Here's a HTML message forwarding sample showing which part can safely be deleted (other messages might contain a preceding plain text part wich can be deleted as well):

I assume the intent is to forward an attachment with it attached to a new message. Are you starting the forward by selecting an attachment in the attachments tab and then clicking the forward button in its toolbar?

I do try to delete the plain text and html text attachments before forwarding. I've just gotten lax about it.

So, is the extra attachments issue not a long time problem for everyone? Is it not a bug? It's been the case for me for many years, but now I hope even more that it can be fixed in a future version, unless there's a reason for it. I do a lot of forwarding. Sometimes people ask what I attached, since it's not something they can read.

And, Brian, I forward from the message view or the list view, not be selecting an attachment.

It has existed for as long as I can remember. The forwarding option "Forward any attachments the message has as well" has always sent the Plain text and HTML text parts unless they are removed before sending. I never understood the reason for them being considered "attachments".

I'm sorry if I'm misunderstanding, but "considered" by us or "considered" by the system and the receiving system?

Mine arrive with these two things listed as "blank image" attachments (along with any other attachments, which have identifiable images and can be viewed or downloaded and viewed) which cannot be viewed/read. And they are listed with the other attachments in the outgoing.

Considered by Pegasus Mail.

Indeed they are listed with the other attachments but mine don't arrive empty when doing forwarding tests to myself. A double-click won't open them but the content is visible in the preview pane.

The only two options I know of that will prevent the transmission of the HTML part and the Plain text part (if it exists) is to delete them before sending or do the forward from the attachments tab selecting just the attachment(s) you want forward.

Hopefully this problem will be addressed in a future version.

For me, the empty generic-image ones are visible in Gmail, after a foreword from Pmail. And I know it happened in some email program before Gmail came to be.

I hope the same, and I thank everyone for their input on this. There are other little things I've just come to ignore/work around, but this is one that bothers people I communicate with, not just being an annoyance for me.

OTOH, if they are showing a blank grey rectangular picture this would be a completely different issue: You would be forwarding a HTML message with remote images which aren't included because Pegasus Mail isn't currently capable of doing so (it can only include pictures already being embedded in the incoming message being forwarded). You can try a workaround by doing a select all of the original message and paste the contents into a new one after downloading the remote pictures but be prepared to see all kinds of weird misformattings if doing so.

Pegasus Mail handles then as expected (not empty, content viewable) but Gmail, via their web interface can't identify them so presents them as per the screen snip below. They are not empty. Hovering over them shows size. Their content is visible in Gmail's "original message' view (what we know as "raw view" ).
I don't know where @theatrenut is seeing them listed as "blank image".

This screen snip is of the attachment section of a forward test message in the Gmail web interface. The forward contained the plain and html pars along with a pdf document of the 2022 recycle calendar for my community.

"blank image" is just my inept description of the gray image that doesn't show what the attachment is (compared to something like your example of the pdf attachment). I am not a technical pro, just a longtime user. Thanks again.