You are going to have to give exact words, a screen shot would be better as never heard of spam alert before in Firefox and it is not a feature that is from Mozilla.

Since do not have send info to Mozilla turned on I do not have info to your Extensions. It maybe a A/V type Extension that is causing the block and it is just some setting you have to change in that program. Or in your full feature Program.

Please let us know if this solved your issue or if need further assistance.

Can you attach a screenshot?

• https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem
• use a compressed image type like PNG or JPG to save the screenshot