Hi, no it is a prepositional phrase. 'for his English teacher.'
Some indirect objects can be moved to the end of the sentence in the form of a prepositional phrase, just like this one.
However, this particular verb/sentence does not allow the phrase to be moved to the indirect object form.
To answer your question, no it is not an indirect object; it is the object of the preposition 'for.' So it is a noun.
I think you may hear from others, however, that this is commonly called an indirect object. From what I have read this is untrue, but it is possible that it is can be called this as this may be quite a flexible term.
Cheers.