This bug shows up in Thunderbird 115.18.0 (64-Bit) on Xubuntu 22.04.5 LTS, but it might be present also in other versions. When I am discussing software topics, I often write emails about what I did and what happened then. I document my findings with pasted screenshots. The emails are HTML-Type emails. While I am composing these emails, everything looks perfectly ok. But once the email is sent, it arrives at its destination without some of the pasted pictures and only with frames showing the sizes of those pictures! When I look op those emails under "sent", some of the later suppressed pictures miss from there. It looks like TB switches to a "loose pictures" mode once and sticks to it for that particular email. It looks like the probability of being hit by this bug increases with the number of pasted pictures. Note: This complaint is different from this one [http://example.com https://support.mozilla.org/en-US/questions/1183434], where it is about pictures copied and pasted from the web (where it might be the case that instead of the picture an Internet link gets posted: My complaint is about pictures not related to any internet source but rather to pictures from my screenshooter utility, which is xfce4-screenshooter (I am on Linux, in particular on Xubuntu 20.04). The first (usually 1 or 2) pictures arrive well at the destination of the email but if the number of pasted screenshots exceeds 4 or 5, the bug shows up. The really bad thing is that when I am composing the mail, everything looks perfectly ok. I can only tell if a mail is affected from this bug, when the email is sent - and then it is too late!