I recently submitted a paper derived from my masters thesis to a journal. Before submission, I sent an email to my masters adviser but did not get any reply. I guess he might have forgotten my name or my email was put in the trash (it happens sometime as I cannot use my school email anymore). I went ahead with the submission as the sole author. The paper was accepted, and when the paper entered the proofreading stage, I sent him another email. This time he replied to me that he would look at it.
Is it ok to publish this paper without my master adviser's name? I have graduated for more than 5 years and did not touch base with him for a while. I used my own money to pay for the journal publication fee and wrote acknowledgment to his effort during my master study.