Provides an additional setting for the option field widgets, so that that the default "- none -" option can be customized, on a per-field and per-form-mode basis.
Mail History modules provides ability to store all sended mails in a database. It has a 'success' field to determine if mail was successfully send or not.
The project is very raw. It only can log all mails in a database now. I wonder if this module would be interesting and useful for people. And also there is api for developers to add their mails to the storage.