A rejected mail for particulating tender

[color=blue]Dear Sir
Unfortunately, we are not able to advise you any offer for this tender due to the delivery period is too short.

Please consider us for your next tender and we apologize for any unconvenience would cause to you.

Thanks & Best Regards,

Dear Alan
The above mail is intended to send to a customer who is inviting us to join to their tender. However, we are not able to meet the delivery time and so my boss decides to pass it. I wonder if you can help me to correct my grammar mistake and advise me if there is any information should be added in.

Thanks for your help,

Hi Kelly,

I attach a suggested version:

[i]Dear Sir,

We regret we are unable to participate in this tender as the delivery period is too short.

We would be grateful if you would consider us for any future tender and apologize for any inconvenience caused in this matter.

Yours faithfully,[/i]