One of my more recent incarnations is as the senior editor for Praxilla, an online literary journal. It's a time-consuming occupation, but a very rewarding one: I've gotten to read and publish some really fine work in a wide variety of genres, styles, and voices by some mighty fine writers. However, as I read through the submissions in the Praxilla email in-box, something that continues to surprise me is the number of people who do not proofread their work and/or follow the submissions guidelines.
Maybe it's because I teach freshman composition, but I'm a bit anal-retentive about proofreading. If I find a typo or misspelling in a post here, for example, I'm red-faced for days. So it puzzles me to get submissions that are literally full of formatting errors, misspellings, and obvious typos. If a writer is that careless about work submitted for publication, why should an editor be careful about reading and considering it? Of course, most editors are careful and conscientious despite any mistakes on the page, but you want your reader (in this case, someone who might possibly publish you) to be thinking about the work, not the mistakes. Also, mistakes look amateurish and suggest a lack of regard for literature as a professional endeavor. Some editors will immediately disqualify a submission with these kind of errors.
We also receive a significant number of submissions that do not follow the (clearly stated) guidelines. Submissions guidelines aren't arbitrary; they are there to facilitate the process of reading, considering, and publishing work. For an online publication, they also reflect the technical side of formatting and uploading files. At Praxilla, we require that all submissions be sent as DOC. attachments. This is because this format is the most user-friendly in regards to uploading work, in particular work with line-breaks and unusual indenting or spacing on the page. Submissions also have to be circulated electronically among the editorial staff, and this is the easiest format for doing this. However, we often get submissions embedded within email messages. This screws up the formatting and makes them a real pain in the ass to upload. So, while it may be easier just to cut-and-paste a poem into an email message, your work may not be presented and read in the way you intended. Also, you risk making the editors cranky because embedded submissions can be hard to read, and that is not a good thing, either. If something in the guidelines isn't clear, ask! Send a quick email, and the editor(s) will be happy to clarify for you.
Finally, most publications have maximum-length requirements. While we don't have a line limit for poetry, we have a 2000-word limit for prose. However, we often get submissions exceeding - sometimes significantly exceeding - this limit. Again, the limits are there for a reason - time, space, philosophy - and to disregard them can suggest a kind of arrogance (my work is special) that is quite off-putting. We return over-the-limit submissions without reading them. Sending them is a waste of both your time and ours (as is sending outside clearly-stated reading periods).
So, if your goal is to give your work the best chance for publication, no matter where you're sending it, read the guidelines and proofread your submission carefully. As your mother said, put your best foot forward. Editors aren't being picky and over-meticulous; they want to focus on the work, not the background noise of typos and misspellings. They also want to spend their time reading your submission, not having to play around with uploading it to the correct format and making sure the line-breaks don't go haywire. Give your submission the kind of professional attention you are asking editors to give to it.
We are currently reading for the next issue of Praxilla. Here are the submissions guidelines. If something isn't clear to you, send an email; we're happy to answer any questions you have. We'll be reading until February 1. We want to read and (we hope) publish your work. Following the guidelines and proofreading make that easier for everybody.