How to post an image on DU using Imgur (without creating an account):

[Make7]

11. There is no longer an expiration on uploaded images.

In the past Imgur would delete non-Pro members' images if they hadn't been viewed for six months (link), but as of a couple years ago they retain all uploaded images unless the user self deletes, a delete requested is granted, there are violations of terms of service/community rules, or an image violates copyrights.

[div class="excerpt" style="margin-left:0px; margin-right:3px; border:1px solid #bfbfbf; border-radius:0.4615em; box-shadow:-1px -1px 3px #bfbfbf inset;"]How long do you keep the images?

Sarah Schaaf - February 16, 2015 20:23

Forever! An image is only removed if deletion is requested.

[font style="font-size:0.85em;"]https://web.archive.org/web/20150920111904/https://help.imgur.com/hc/en-us/articles/201476457-How-long-do-you-keep-the-images-[/font]
A quick search turned up this image I uploaded almost 5 years ago:

https://imgur.com/k1sDT    (Uploaded Jun 16 2012)

(imgur was started in 2009)