Dear :

Thank you for your order of [date] for [products].

We regret that we are unable to fill you order immediately, as the items you request are temporarily out of stock. We anticipate that we'll be able to fill your order in weeks and we will inform you when the goods are ready for delivery.

We are sorry for any inconvenience that may be caused by this delay. Please contact me directly if there's anything I can help.

Sincerely yours,

[name]

[title]