Acceptance is the final and unconditionalagreement to all the terms of an offer.
Acceptance cannot be silence (Felthouse).
An offeror can require a specific form of acceptance although these requirements can be waived (Yates).
Auto generation in an email can be the same as a signature on paper (Rees).
The postal rule stated that where post is the usual form of communication and it has been properly addressed and stamped, then acceptance is at the time of posting (Wells).
In any other circumstances, acceptance occurs when the offeror is aware of the acceptance (Entores).
Electronic acceptance occurs when the message is opened (Brinkibon)