Dear Felix
It has come to my attention that your order of [DATE, ex. May 27] for [LIST PRODUCTS, ex. 5 Magna flux compressors] was delivered late on [DATE, ex. June 27]. Please accept my apologies and let met assure you that our company otherwise has a favorable record of delivering by the date we specify.
I hope the delay did not cause you much inconvenience and we look forward to serving you again. Feel free to call me at XXX-XX-XX if you have any concerns you wish me to address.
Regards
Lydia