Perhaps others might like to add their own examples of pbem commentary in turns sent.
My most recent pbem game as the CSA had Jackson's "fire brigade" Corps hounding US Burnside's Expeditionary Army across the south from attempted landings at Mobile (aborted), Penascola (driven off), and finally St. Augustine Florida with Jackson declining to contest it to deal with a Union landing at Beaufort SC instead. Herewith my comment to my opponent on Burnside's expedition:
Re Jackson's Great Southern Tour--I see Burnside is doing the same, looking for easy pickings after Fort Pickens--a bad pun but I couldn't resist--and finally opting to land in Florida.
Harvey Hill, sitting around the campfire with Longstreet near Fredericksburg, with wry humor dubbed the blood-thirsty swarms of mosquitoes Burnside's men were in for, "as true and effective a cadre of relentless partisans and bushwackers as the South could wish for," suggesting John B. Floyd be promoted "General of Mosquitoes," and sent south post haste--prompting a loud guffaw from Pete and the other generals present.
(I had originally called this a "fifth column" but I don't believe the term came into use until the Spanish Civil War much later. In any case I trust the mosquitoes and malaria will decimate Burnside's expeditionary army, expeditiously as it were.)