That doesn't mean his consent isn't required.
You can, if you prove to a court that all other avenues have been exhausted, to publish your intent.
Has the mother agreed or been declared unfit?
You will find that having to ask questions a second time is an excellent way to get this board to withhold it's help.
MS allows for termination of parental rights on the basis of abandonment:
Stepparent Adoption in Mississippi
It may therefore be possible to adopt the child without the father's consent if the court agrees that he has abandoned the child. However, that's going to depend on a great deal more info. So the father hasn't seen or heard from the child. Is the child at the same address as when the father WAS involved or has the child been moved?
There are a lot of other questions that need to be answered, as well:
- What is the current custody / visitation order.
- Have the grandparents been part of the child's life to date?
- And, as you asked, where is the mother in all of this?
- Do the grandparents have court-ordered visitation?
- Has visitation with the grandparents ever been denied
- Are the grandparents able and willing to take proper care of the child and raise him to adulthood?
OP still needs to answer the questions to get useful advice, though.