Maxsubjectlength

Maxsubjectlength is a software configuration parameter that specifies the maximum allowed length, in characters, of the subject field in a message, ticket, or thread title. It is commonly used in messaging systems, email clients, help desks, and issue trackers to enforce input constraints and maintain readability.

In practice, the parameter is consulted at subject creation or update time. If the user-supplied subject exceeds the limit, the system may reject the input with an error, or automatically truncate the subject and optionally append an ellipsis. Some implementations count length in Unicode code points, while others count bytes, leading to differences with non-ASCII text.

Best practices include counting characters rather than bytes, handling combining characters and surrogate pairs, and offering a user-friendly message indicating the limit. Consider whether the limit should apply to the raw subject or to its rendered display, and how it interacts with languages that use longer phrases.

Common use cases include customer support portals, issue trackers, CRM messaging, and automated email generation. While the exact value of maxsubjectlength varies by system, values commonly range from 40 to 200 characters, depending on UI space and readability goals. The setting can be configured globally or per project or tenant.