Hello Madam/ Sir, My Son is travelling from Honolulu to Boston via Hawaiian Airlines flight HA0090. But this flight is landing at Terminal E. So, does he need to pass through immigration? This is within US so it should be domestic flight.

Honolulu is considered domestic flight, no immigration forms required.

No he shouldn't have to through immigration. Well I don't so.

Terminal E is the INTERNATIONAL terminal! I guess your son will have to go through passport control, even if he is curious to see a domestic flight arrive there. The reason could be that your son is going to take a flight from a foreign country, before landing in Honolulu.

Should only be an agricultural check, if even that.