Adds information to the block of correspondence participants about the last time a correspondent opened it.
Addon just copies this feature from IPB3.
And, although by default XF saves information about the last reading of the dialog, it sets the date of the last message left as a date. To fully simulate the behavior of IPB3, an option was added to the settings to enable saving the current time as the date, not the time of the last message.
By default, this option is disabled.
Option placed here: