Solved

Deleting Archive Mail!

When I delete an archived mail, the delete button fades (which signals it has deleted) but when I go back on the mail, it is there. I am not sure if this js classified as a bug but it is quite annoying and the mail can be a bit of a nuisance at times. 

I just tried this in the android app (v3.2) and don't see the same behavior. 
On which platform do you see this? Android/iOS/PC? Which version of OS and app (in case of app).

When you click on delete, normally you get a pop-up, asking to confirm or cancel, this is at the same moment when the button fades. Do you get that?

Using android, the confirm tick/cross comes up, but when the tick is pressed, the delete button fades but the mail remains. I will find android version shortly. 

a new android version got released tonight, so certainly try updating to that also.

If it then doesn't work yet, please tell us your device model and android version.
And if you can, a little video of what you are doing and seeing would be great :)

I have just updated but the issue remains.
I have a samsung J3 and android version is 3.2

Ok. Thanks for the help!