Graham has decided to sell his house. Matt contacts him on $8$th October to say that he is interested in buying the property but that he needs time to speak to his bank manager to see if he can borrow $110,000.$ Graham agrees to give him time to think over the purchase, and promises to keep the house for Matt until $15$th October. On $10$th October, Graham receives an offer from Montgomery to buy the house for $120,000.$ Graham replies saying that he will accept his offer at $125,000.$ Montgomery says he will not pay 'a penny more that $122,000\text{'}$ for it$.$ Graham wants to think about this offer overnight.

On $13$th October he writes to Montgomery accepting his offer to buy the house for $122,000.$ After posting the letter, he telephones Matt to tell him that the house has been sold. Later that day, Graham receives a telephone call from Montgomery saying that he has changed his mind, and is no longer willing to pay $122,000$ for the house. Graham explains that he has just posted a letter of acceptance to him. Meanwhile, Matt is furious that Graham has sold the house before he even had a chance to speak to his bank manager.

Advise Graham and Matt.

Would it have made any difference if Graham had e$-$mailed his acceptance to Montgomery on $13$th October instead of posting it$?$