I have done this and been testing it for a few days with limite_falha set to 10 (20 minutes) and have been getting emails roughly each day saying its stopped sending, followed by another email 10 minutes later saying its working again so this seems to have fixed the error
i will change it to 8 when I get chance and this should keep it going without emails so I only get emails if there is a new problem.
I have ordered a new screw shield and ethernet shield as well just incase my ethernet is at fault and to tidy it up so fingers crossed this will be out of test soon and properly running the tank.
Thank you again for all your help. You have done a sterling job creating this software