I'm not famililar with .netrc, but the mainframe does have several ways to perform automatic FTPs.
There is an FTP program you may invoke from batch jobs where you provide the FTP commands in a series of input cards. The good news is you can use this method to send and receive files from a scheduled batch or ad-hoc jobs. The problem is that the control cards aren't very flexible and, depending on your security set up, you may have to include the password in clear text. Some of these deficiencies can be avoided if you write another program to create the control cards on the fly before passing them to the FTP program.
You can also write your own program using FTP's protocol. This gives you a lot more flexibility dealing with errors and different servers. It is also more secure.
In either case, get in touch with some mainframe friends or look at the appropriate IBM manuals.
This was first published in September 2007