OnCustomFTPProxy is a TNotifyEvent property that represents the event handler signalled to allow support for connection and authentication using custom FTP proxy server types in the FTP client. 

OnCustomFTPProxy is triggered in the Login method when the TIdFtpProxyType enumeration value fpcmCustomProxy is found in the ProxyType property in ProxySettings. If OnCustomFTPProxy has not been assigned in this circumstance, an EIdFTPOnCustomFTPProxyRequired exception will be raised. 

Applications can use OnCustomFTPProxy to implement the complete FTP protocol exchange required to both establish the proxied connection and to perform authentication for the client session. In general, the FTP protocol exchange should be performed using the SendCmd method to allow capturing responses in the LastCmdResult property. Please note that the final response in the exchange is stored in the LoginMsg property and passed as an argument to the OnBannerAfterLogin event handler. 

Use of the OnCustomFTPProxy event handler is not required if the FTP proxy server is one of the types supported in TIdFtpProxyType.

LastCmdResult 

Login 

OnBannerAfterLogin 

ProxySettings 

SendCmd 

TIdFtpProxyType 

EIdFTPOnCustomFTPProxyRequired