SMTP from a desktop client

I need to send an email from an external application. I am using SMTP and I did manage to add the IP I was sending from in number of exceptions. For SPF, Greylisting and Relay exceptions. This is really inconvenient. Isn’t there a place where I could just specify the IP once and all rules will be ignored.

I still have a problem though because in the message header in the receiver’s email I can see the receiver’s server does SPF check on the machine I am sending the email from. So is there are way to somehow overwrite the sender IP with the server IP so when the remote server does SPF check they will do that on the sending server IP?