Correspondence that carries a reference number and stays with the project. RFIs, site instructions, notices and extension of time claims usually live in personal inboxes, and when someone leaves, the history leaves with them. Not here.
Types and numbering
A project runs several mail types, typically Correspondence, RFI, Transmittal, Site Instruction, Direction, Notice and Extension of Time. Each type has its own prefix and its own sequential numbering, so an RFI is identifiable at a glance, and each carries its own custom fields. An RFI records a priority, a discipline and a required-by date; an extension of time claim records the cause event date, days claimed, days approved and the contract clause. That is what makes the register reportable rather than just readable.
Threads
A piece of mail grows into a thread. Replies stay in it, keep the same reference number, and carry the status with them as it moves between Open, Under Review and Closed. The whole exchange sits in one place, in order, rather than in a forwarded chain nobody can reconstruct.
Composing
Pick the type and the next number is assigned automatically. Address it to individuals or to a distribution group, write the body in a proper editor, fill in the required custom fields, and attach documents straight from the project register so the recipient gets the current revision. Your signature is applied based on whether this is new mail, a reply or a forward.
Drafts
Save instead of sending and the item waits in Drafts, visible only to you. Useful for a notice you want a colleague to read first, or a claim you are assembling over several days.