The number of photos allowed per envelope varies by facility and is set by the individual institution's mail policy rather than a universal rule. La Palma Correctional Center in Eloy is a private facility operated by CoreCivic, and their specific photo limits are worth confirming directly before you send anything.
The most reliable way to get that answer is to call La Palma directly and ask the mailroom or a counselor what the current photo policy allows per envelope. Facilities typically have limits somewhere between five and ten photos per mailing, but that number can be higher or lower depending on the institution and whether the photos are printed on standard photo paper versus other formats.
InmateAid's photo service is a straightforward way to send photos without worrying about format requirements on your end. The photos are printed on standard photo paper in high quality and sent through the normal mail channel, which means they arrive in a format the facility is accustomed to receiving and processing.
If you want to maximize how many photos reach your inmate in a single mailing, confirm the facility's limit first, then send up to that number through InmateAid. Sending more than the allowed amount typically results in the extras being confiscated or the entire envelope being returned, so knowing the limit before you send saves you time and money.