Same issue for me too. My boss is telling me to stop using Airmail. It doesn't appear when I'm sending it, nor does it appear when they reply. But when I reply to them it definitely creates weird attachments of email signature images. If the recipient is in Gmail, it does NOT show paperclip attachment but it DOES show actual attachments.
I've tried changing my email signature images to be HTML links, but Airmail will still create them as attachments when I reply to a reply.
Closely documented and asked the dev team twice, but they don't seem to be interested in fixing it. Not surprising given that Airmail isn't exactly expensive. I would really want Airmail app to become subscription service and just be more responsive to all these bugs.. great design, many bugs, and bad composer usability.
I've tried creating signatures both by direct drag-and-drop images and pure HTML. Both experienced same issue - my email threads start to show weird attachments, that are actually images in the signature. Every time a back-and-forth correspondence happens, it piles up - so I have 6 images on my signature, that became 12, 24, 48.. etc.
On Gmail, paperclip icon does NOT show up on the list view, but once you click into see detail view of the thread, you see MANY attachments. If there's an actually attachment, it shows the icon, and when you go in to see the detail, it's very hard to find the attachment because of all the other weird attachments.
Hoping this version solves t his.... I wrote about this issue in both request/bug forum and sent 2 emails to support about it..
Didn't work for me either. An attachment with a coded name is sent whenever I send an email from Airmail Beta with a logo in the signature. This coded attachment is not visible as an attachment in Airmail, but it's definitely there when viewed in Gmail.
Just to be clear, I'm using a Gmail account (G-suite) to send an email with a logo in the signature.