There is a very similar question here (How can I remove all traces of my original Gmail address from a “send mail as” alias?) although mine is about transferring between different Gmail accounts, and I also want this change to be reflected in past e-mails. To clarify, this is also only Gmail-specific, regardless of Apps service.
My old address was something like email@example.com, and I now want to transfer everything to Name.Surname@gmail.com
Following these instructions (https://support.google.com/mail/answer/21289?hl=en&rd=1), it seems to work fine, except that it shows the firstname.lastname@example.org in the sent to section of the header.
Is there a way to solve this issue?