The content of the post was deemed irrelevant to e621. Most often this happens because there are no furries, animals, or other fantasy species depicted.
If a post either contains no characters at all (think landscape painting ala Bob Ross), or has only humans then the post will be deleted for this reason. Non-human creatures must also be part of the focus of the image, it is not enough if the creature is just in the background.
Another possibility is that the post contained things like a youtube music video, screenshots from games/movies, or similar non-artistic content.

Please note that any traditional art besides drawings are not permitted on e621, this means that things like sculptures, plushies, wood carvings, etc. will be deleted.

For more information on humans and e621 please check here.

The artist or publisher of the image / animation has elected to be placed on our Avoid Posting List (short DNP list).
There are two Do-Not-Post statuses possible: full DNP (signified by the avoid posting tag) and conditional DNP (signified by the conditional dnp tag).

The full DNP status means any post the artist has created, or has collaborated on, will be deleted.

The conditional DNP status means that any post exceeding the limitations of the granted DNP status will be deleted.

This deletion reason means that one (or more) parts of the post aren't of high enough quality for our archive.
The most common problems are:

Artistic quality

• anatomy that makes no sense
• legs/arms of different length, head/body ratio is way off, one eye lower/larger than the other, hands of different size, broken ankles, that sort of thing
• "but it's my style" only works as an excuse if the style is coherent in itself, arms that are of different length are seldom a stylistic choice
• scribbles
• sketches are fine, but even doodles need to look better than something drawn hastily into the corner of your math homework
• coloring outside of or over the lines
• "1000 hours in MSPaint"
• those are usually troll images that look like they took about 5 minutes in paint while being drawn with a mouse during an earthquake
• coloring any base (template linework created by an artist) is not acceptable and any of those will be deleted
• however, we do allow up to 5 instances of those bases if they have been created and finished by the original artist

With how simple it is to use SFM to create halfway decent 3D artwork we have some special considerations for those:

• simply importing a pre-made model is not acceptable, the model(s) must be properly posed
• the pose chosen must look as natural as possible without any clipping or deformed joints / body parts
• textures must be of good quality and actually somewhat match to each other (no checkers board dick on oiled up skin models)
• animated loops must at least loop decently without extreme jumps between start and end point(s)

File Quality:

• visible compression artifacts^[Wikipedia]
• The FPS of the file is too low (for example less than 5fps for a very hectic animation)
• A file conversion was done badly (for example recording a playing video through screencapture to create a gif, or submitting a screenshot of something you found on the internet)

This means the submission you uploaded is either a duplicate of an already existing post, or in some way inferior than another post.
This can be that your upload has a smaller resolution, has worse compressions, an older wip of a finished work, or has been tampered with in other ways.

On the deleted submission you can click the parent link in the upper left corner to view the superior version.

When uploading drawings, you need to use a scanner. Do not upload images taken with a cell phone camera. Only a professional-grade camera used in a brightly lit studio can match the quality of an ordinary flatbed scanner.

Uploading a scanned version of a previously photographed image does not guarantee that the post will be approved. Poorly drawn images don't become good just by being scanned.

Scanners can be found for under $100 and as printer attachments. You could also check Freecycle, Craigslist, or one of your local libraries to look for a free scanner.

Mostly the same as quality, but the edit itself must have at least the same quality as the original artwork. Simply slapping on some text, blanking out a speech bubble, or pasting genitalia from a different artwork are not acceptable.

Any sort of screen capture may fall under this including screenshots of games, recorded gameplay videos, taking a video with your smartphone of a TV screen, etc.