Yes, Optimum Online (optonline.net) email accounts have a storage limit. Each email account is allocated 5 gigabytes (GB) of storage space. Once this limit is reached, the account will no longer accept new emails, and incoming messages will be returned to the sender. To manage your storage effectively, regularly delete unnecessary emails and empty the trash folder. Additionally, be aware that email accounts are considered inactive if there is no activity for 120 days, which may result in the deletion of all email content.