I suppose it is a matter of personal interpretation. Is the raven real or imaginary? It seems to me that there is too much detail for the bird to be imaginary. It might seem a little odd that a big black bird would appear at the window on a stormy night, but it is not utterly fantastic. The speaker himself speculates that the bird is a tame one that somehow escaped from confinement and is now seeking shelter in a human habitation which it associates with safety and food. Tame birds that get free frequently seek shelter with other human protectors. If it perched up high on a bust of Pallas, that would be understandable because it would be likely to want to survey the new quarters from a safe distance. If it could only speak one word, that would not be too far-fetched either, because ravens are not noted for having the vocabuary of parrots. If the speaker thought he was going crazy, he would probably give more evidence of that thought in his poem. The raven, of course, is not real; it was created by Poe's imagination. So to ask if it is "actually there" is asking whether Poe intended for it to be "actually there." If he intended it to be a figment of his speaker's imagination, I believe he would have given some clues. For example, at the end he might have said that he fell asleep and when he woke up the bird was gone. Authors frequently do that sort of thing. "Was it real or was it only a dream?" I believe the reader of the poem thinks it is a real raven, at least during the time that he is reading it. If the speaker is crazy, then maybe the reader is crazy.