From a seminarian:
A priest at the seminary has been blessing saying "May almighty God bless you in the name of the Father, the Son, and the Holy Spirit."
Another priest mentioned this was wrong and even heretical for a priest to bless at this part of the Mass "in the name".
Do you know anything about this?
I don’t know about heresy, but I do I know this:
I believe the missal has a form to be used by the priest at the end of Holy Mass: Benedicat vos omnipotentis Deus, Pater et Filius et Spiritus Sanctus… May Almighty God bless you, the Father, the Son and the Holy Spirit.
I would therefore wonder if the priest just didn’t pay adequate attention to the book and never really double-checked the proper form,… which is likely… or whether on his own initiative he decided that he knew better what the Church should do and changed it.
Surely once he finds that he has been doing something wrong he will make a change.
Back to the question of heresy. I am not sure in what the heresy would be found.
There are other blessing forms, but I cannot call to mind one whereby the priest blesses "in the name" of the Trinity. Priests call down invocative blessings but seemingly in their own name. Either way, God is doing the blessing at the invocation of the priest.
Perhaps a reader or two might have something useful to contribute on this point.