Answered by Shaykh Faraz Rabbani
Question: When is the offer/acceptance considered sent and recieved when it is through written media like emails, text messages or the like?
Answer: In the Name of Allah, Most Merciful & Compassionate
Walaikum assalam wa rahmatullahi wa barakatuh,
A valid offer sent by email, SMS, IM, or other electronic means is considered to have been made upon the sending.
It is considered to have been received when it is read by the receiver.
The fatwa in our times, as elucidated by Mufti Mahmoud Ashraf and other scholars of verification (`ulama’ muhaqqiqin), is that a written offer remains until there is actual rejection from either party, rather than the more famous opinion in the school of immediate acceptance within the majlis.
This opinion is related by Ibn Abidin in his Hashiya from leading fuqaha’ of the school–and a number of commentators on the Majalla, including Allama Atasi mention it. Affirming otherwise, given the nature of contemporary commercial transactions, would not appear to be sound fiqh, as Mufti Mahmoud Ashraf put it.
And Allah alone gives succes
(Originally answered on the SeekersGuidance Academy’s Islamic Law for Seekers: Transactions Course Forum)