So I've loaded up RTS and I keep trying to load the Mailbox but I always get an error. Here's my load order from FOMM

Fallout3.esmAchorage.esmRTS.esmThePitt.esmBrokenSteel.esmPointLookout.esmZeta.esmMothership Crew.esmCALIBR.esmSomePoses.espFO3 Wanders Edition - Main File.esmLevelers Truck Trailer.espMZTweaks.espKikaiEquipment.espMesmetron Works on Everyone.espConsoleMod3b.espMMM.esmMMM.espMMM - increased spawns.espMMM - increased increased spawns.espMMM - Hunting and Looting.espMMM - Feral Ghoul Rampage.espMMM - Tougher Traders.espMMM - No corpse flies.espMMM No Ghoul Raise.espFo3 Wanderers Edition - Main File.espMMM - No Geckos.espMMM - No wannamingos.espMMM - no Floaters.espMMM - No Skeleton Decay.espMMM - Natural Selection.espMMM - Zones REspawn.espMMM - DLC anchorage.espCraft.esmMMM - DLC The PittUsableCigarettes.espMMM - DLC Broken Steel.espZAT.espZumbs' Console Mod.espStealthboy Recon Armor - CRAFT.espCRAFT - Activation Perk.espsc_slaves-stick-around-original_mezz.espGrouse Slaver Radio.espFellout-BrokenSteel.espFellout-Pipboylight.espFellout-Full.espMiniHideout.espSharing and Caring Companions.esmFNN01.espWeaponModKits.espTenpenny_Tower_Security.espAlternate Start - Roleplayers.espFNNCQ.esmWinter Wonderland.espAsharasBatmanItems.espCALIBRxMerchant.espZombie Apocalypse.espTelsa Stun Gun.espMonster_Costumes.espRTS_Life_Of_Raider_Addon.espSarah Lyons Companion.espAttentater's Wateland Economy.espF3UmpaAnimation.espThe Groovatron.espMilitia - Megaton.espChekovs.espRTSpatch_RVW.espTEHL.esp

Disable "Life Of a Raider", it is for an older version of RTS. Also, with the mods you are using, you should definitely be using a merged patch. Make one with Fo3EDIT. That should help with the errors.