Using Mail In Payment as a gateway will give you a text area to enter payment details for the client. This can be used to show your address for clients to send checks or money to you.
When you receive the payment, you would need to add the transaction manually into WHMCS by using the Add Payment section of the invoice.
Server Modules
cPanel/WHM - DirectAdmin - Plesk - Helm 3 - Helm 4 - Ensim - InterWorx - DotNetPanel
Lxadmin - Virtualmin Pro - XPanel - HyperVM - FluidVM - SolusVM - Cloudmin - WHMSonic
CentovaCast - SCPanel - CastControl - GameCP - TCAdmin - Reseller Central - Auto Release
Registrar Modules
Enom - ResellerClub - Nominet - OpenSRS - ResellOne - OnlineNIC - PlanetDomain
DistributeIT - TPPInternet - RegisterFly - Stargate - Namecheap - NetEarthOne
12Register - Registercom - DotDNS - WebNIC - Dot.TK - HexoNet - Realtime Register
Fraud Modules
MaxMind - VariLogiX FraudCall - Telesign
Selected Gateway Modules
Payflow Pro - Authorize.net - BluePay - Quantum Gateway - eWay - eProcessingNetwork
InternetSecure - LinkPoint - SecPay - ProtX - PSIGate - WorldPay Invisible - NaviGate
Merchant Partners - PayOffline - Offline Credit Card - PayPal - ChronoPay - 2CheckOut - Google CheckOut
WorldPay - E-Gold - Gate2Shop - F2B - PagSeguro - NoChex - AlertPay - ProtX VPS Form - Paymex
CashU - Liberty Reserve - StormPay - Paymate AU and NZ - Payson - BRPay - Boleto - MoneyBookers
PayOffline - Mail In Payment - Bank Transfer - USA ePay - Pay Junction - PayPal Website Payments Pro
