If you insist on keeping your @nyc.rr.com email address then you can try using Gmail's SMTP server to send messages through. This workaround is easy and free but it does slightly increase a chance that your messages will get flagged as SPAM on the receiving end. Very slightly, though. Here's how it works:
1. If you don't already have free Gmail account then create one and log in.
2. In Gmail's Settings > Accounts tab, find an option to add an email address to send messages from.
3. Complete all the necessary steps to add your @nyc.rr.com address.
4. In your iPad, replace smtp-server.nyc.rr.com with smtp.gmail.com and SMTP's username/password with Gmail's username/password, also Use SSL should be On, authentication should be Password, Server Port should be 587
5. Make sure to send a test message from iPad and verify that it indeed comes from @nyc.rr.com address. If they appear to be coming from @gmail.com then double-check steps 2 & 3.
6. If you never intend to check this Gmail account then as a precaution I suggest you forward all incoming messages to your @nyc.rr.com address.