The 5th trait bonus of Sergeant's Mail is removed from cleanse or any skill that removes negative effects. The only way to get the bonus back is to re-equip a piece of armor.
Here is a short video showing the issue. I have no buffs on and attack doing 4209 damage and then I cleanse, removing the sergeant's mail bonus, and I do 2570 damage.
https://www.youtube.com/watch?v=3NdE5MSP3D0@ZOS_GinaBruno @ZOS_KaiSchober I think the bonus is being considered a negative effect and is being cleansed. Can I please get some acknowledgment on this? I have brought it up before to no avail but now i have proof.
Update 9/13/2016: From xbox patch notes today "Sergeant’s Mail: Fixed an issue where this item set’s 5-piece bonus could be purged from you."
You guys fixed this within in a month. I am astonished! Thanks ZOS!
VR14 DK Leaps-in-keeps