Well hmm...an e-mail is not very formal.
Here is an example of a formal diplomatic letter:
Foreign Ministry,
Kingdom of West Verklempt
To:
Hon. Lupo Strelski
Foreign Minister,
Republic of Buttwind
Your Excellency, Greetings:
This message is in reply to your message regarding diplomatic relations
between our two great nations. I am quite pleased to announce that,
with the approval of His Majesty, King Maximilian XXVIII, the Kingdom
of West Verklempt would be quite amenable to the formalization of
diplomatic relations with the Republic of Buttwind.
An exchange of ambassadors will be the natural next step in the
diplomatic process. Please contact me at your earliest convenience to
make arrangements for this exchange.
Respectfully,
Count Kurt Krellnikov
Foreign Minister,
Kingdom of West Verklempt