Dear Felix
I am deeply embarrassed for missing our meeting on [DATE, ex. June 10]; please accept my apologies. As you understand, I was unable to attend because [STATE REASON, ex. my flight was delayed five hours due to unfavorable weather in San Francisco]. I was looking forward to discussing [STATE SUBJECT OR TOUT YOUR PRODUCT/SERVICE, ex. how our Magna flux compressor can cut your manufacturing costs by up to 30%].
I would very much like to set up another meeting with you. I am available on [LIST DATES AND TIMES YOU ARE AVAILABLE, ex. June 11 to 15, any time before 4:30 PM]. Please tell me when is best for you. You can reach me at XXX-XX-XX.
I am looking forward to hearing from you.
Regards
Lydia