No, of course it won't keep changing. It was originally set to a @softhome.net address, but I had to change that because SPF won't allow the forum server to "lie" about its address. Now it's set to @msghelp.net, which is accepted by SPF, so I guess it will stay like that unless there are problems.
Unfortunately, in order to make SPF happy, I now can't recieve mailer errors and stuff, because I can't view the mails that msghelp.net recieves.