They will have to tell you. The jails do not report back that incoming mail was received. If there are any issues we will resend with no questions asked. Normally it takes 2-3 business days but the staff ultimately has the responsibility of deciding when they hand out the mail. Delays happen sometimes without notice.
https://www.inmateaid.com/ask-the-inmate/how-can-i-tell-if-an-inmate-received-my-postcard#answer
Accepted Answer Date Created: April 14,2016