I spent four or five hours yesterday preparing a poetry submission. I don't know what getting subs together is like for other poets, but for me it always takes a long time because I want to be absolutely sure I've got the right poems for the magazine or website I'm submitting to; I also have to be sure that the poems are as good as they can possibly be, with no lapses in rhythm or slack phrases, no bad grammar that I can't justify as experimental poetics. I'm tremendously insecure about everything I do as well, so once I've completed every job I set myself prior to submission, I'm usually stricken with doubt and gripped by a compulsion to look over everything again. Which isn't great for someone who has blinding headaches and seizures when they read for too long.
It happened that way yesterday (not the seizure part, mercifully, but the rest of it). So did something which other poets have told me they experience: as soon as I hit the 'send' button on my email I realised there was a line in one of the poems that I needed to change. This happens to me constantly and it drives me insane. But you can't send a pleading email to the editor. He or she probably gets twenty or thirty emails from poets a day and has neither the time nor the patience to nursemaid your insecurities. They might hate all of your poems anyway, which makes the request to tweak a line in one of them rather redundant.