A) you can add images to your posts here; no need for 3rd party sites. ;-)

B) Save a message in Drafts, open it there, use ctrl+u to see its source. Search for any occurrences of trigger words, which are listed here:

Tools|Options|Composition|General→Keywords

Is there anything in your signature that provokes it? Do you use any templates or stationery?

Hi,

Sorry about that image link.

I don't think that is my signature that triggers the attachment notification because I'm using 4 accounts on my thunderbird (2 of them without signature) and the notification is always triggered when composing a new email.

Btw, since I posted this question, I found 3 other people that had the same problem.

Thanks in advance.

I was one of the persons with the same problem but already solved it.

In my case the problem was related with the signature file but I'm not sure what the problem was.

I solved it this way: 1) create backup of signature file. 2) clear all content from the signature file. 3) restart thunderbird and see if the problem still exists. In my case it didn't. 4) add a content to the signature file tag by tag (in my case as it is html) and repeat #3.

This way I was able to put exactly the same content as before (!!) but no more attachment alerts.