Dear Felix
On [DATE, ex. June 5], we submitted our purchase order #[PURCHASE NUMBER] for [PRODUCT (S), ex. 3 Magna flux A5 compressors]. Although [we requested / you estimated] delivery by [DATE, ex. June 20], [REASON, ex. changes in our forecasts] have caused us to require the shipment by [DATE, ex. June 15].
We understand that this request may place some burdens on your schedule. For that reason, your accommodation would be greatly appreciated. Please contact me at XXX-XX-XX if this is not possible.
We look forward to continued business together.
Regards
Lydia