Changing submission email

[japamor]

Yes, it sounds like you should change.
There shouldn't be any problem with any sensible LL as long as you inform them what's happening. They'll quickly get used to your new email. And yes its best to use the same email, even when submitting from a different domain. Again, let the LL know that although the domain is different, the submitter is the same, known, person.
It all comes down to communication really.