The most common problems with poetry are, oddly enough, not with the format (although there are people who do not know what rhyme actually is, and still try to write rhyming verse) but with the force behind them. A haiku such as:
Eating up our resources
We will all die soon
contains the right number of syllables, but expresses no genuine understanding of the force which drives a haiku:
A tree in starlight
May not be seen by men’s eyes
But still casts shadows.
Which is not particularly good, but contains more of the idea of a haiku than the first.
When it is unrhymed, less formal poetry, the problem of what drives the poem still emerges:
Up in your lap
is just a sentence about cats cut up into five lines. This isn’t poetry.
Another major problem is one which is shared by the short story. Many of the writers simply haven’t read very much poetry, and so they present tired old tropes with effervescent belief in their originality. We are all familiar with the idea that the ecology of the world is being screwed, so any poem which takes this as its theme had better shed some new light on it.
But keep sending the poems in. Most poets find that they write fifty poems before they write one that works.
Poetry submitted to a speculative fiction magazine should contain some speculative fiction.
Andromeda Spaceways prints science fiction, fantasy and supernatural horror (or any reasonable combination of the above). Poetry submitted to us should have something to do with those themes.