|daily-image-l is the name of an announce-only mailing list that provides a daily update on the Commons:Picture of the day. It started on the 17th of February 2007, and in less than four months gained over 500 subscribers.
List feedback can be posted on this talk page.
Questions and answers 
How very mysterious! This seems to be mainly a problem with Gmail, but it has happened with other mail clients. Please email the list administrator with details about your email client and any other software that might interfere with your email such as spam-blocking software.
At any rate, you can always jump to today's POTD with this link: http://tools.wikimedia.de/~daniel/potd/potd.php/commons/home
And if that ever fails, you can view today's POTD here: Commons:Picture of the day/Today (but you'll have to click through to get the image page).
How are Pictures of the day chosen? 
Since January 1 2007, Pictures of the day are chosen from images that have been recognised as Featured pictures or Quality images. Anyone can make one of these images a Picture of the day. If you have an Featured picture/Quality image that you want to make a Picture of the day, go to Commons:Picture of the day and find the next day that does not yet have a Picture of the day set. (This might be a month or so in the future.) Only images that have not yet been a Picture of the day are eligible. Follow the red links and insert the image's name.
How does an image become a Featured picture or Quality image? 
Featured pictures are recognised as "the best of the best" and go through a two-week nomination process. Anyone can nominate an image to be a Featured picture at Commons:Featured picture candidates. However, only registered users can vote on these nominations. (To register, go to Special:Userlogin.) A nomination will result in a Featured picture if the ratio of support:oppose votes is 2:1, and there are at least five support votes.
Expected standards are high. New nominators are recommended to read through Guidelines for nominators and spend some time looking over the current nominations and comments, to get a feel for what will be accepted.
Quality images is a related process that is only for self-contributed work, and evaluates more quantitative technical standards rather than requiring "outstanding" artistry. Detailed guidelines exist; images can be nominated at Commons:Quality images candidates.
Fantastic! Here's how:
- Find the language code of your language on Special:Sitematrix (e.g. English is "en").
- Go to Picture of the day page. You'll get each Picture of the day for that month, with your language's caption aside the image. If it doesn't exist yet, it will be a red link. Just follow that link and write a short sentence describing the image.
If you have trouble, you can leave a comment on this talk page or the Help desk, and someone will try to help you.
If you're interested in translating other material for Commons, please see Commons:Help page maintenance.
All translations that exist the day before, will be sent out in the daily email.
I want to translate the mailman (mailing list) interface into my language. 
That's great; to get involved with that project, check out http://wiki.list.org/display/DEV/i18nhowto .
Who can contribute material to this website? 
Anyone! We especially welcome people who contribute their own work, be it photographs, maps, diagrams or any other media. Material here should be useful for a Wikimedia project (typically, Wikipedia). To find out if your work is appropriate here, please read our Commons:Project scope policy.
We recommend new users read through the Commons:First steps guide.
Am I allowed to re-use these images? 
Absolutely! All material here is available under the terms of a free license, or in the public domain (ineligible for copyright). In practical terms, this means that you can use any image for any purpose, including commercial uses and the creation of deriviative works. Some conditions may apply, such as attribution (you must say who the author is), sharealike (any deriviative works must be released under the same free license) and copytext (any use of the image must be accompanied by a full copy of the license text). Please read the terms of any particular free license to find out what is requires. These licenses are usually written in "human-readable" format and are not full of legalese like some documents.
Another question not covered here? 
Post it on this talk page.