Which event is in dispute?
A sent item, a transport record, a delivered mailbox copy and evidence that a person read a message are different things. Identify whether the concern is the sending time, acceptance by a server, availability in a mailbox or a named person's awareness of its contents.
Relevant sources
Native messages, available transport or gateway logs, mailbox copies and related correspondence may help reconstruct the sequence. Preserve original timestamps and timezone offsets. Client displays, export tools and server records may represent different events or apply different timezone conversions.
Interpret cautiously
A sender-supplied Date field does not independently prove when a recipient received a message. A read receipt or logged interaction may need contextual assessment and does not automatically identify the reader. Missing records can prevent a conclusive reconstruction. Begin with the precise event to be established, the relevant parties and the source of each time value. An agreed chronology should identify the meaning of each event, any normalisation applied, contradictory records and uncertainty in the ordering.