Asking sorry for not mail

You're apologizing for not sending a letter or mail. Here are a few examples of how you could phrase your apology:

• "I'm so sorry I didn't send the letter/mail as planned. I feel terrible about it."
• "I apologize for not getting the mail out on time. I know you were expecting it."
• "Sorry to say, but I didn't end up sending the letter. I'll make sure to get it to you as soon as possible."
• "I'm really sorry I missed the deadline for sending the mail. Please accept my apologies."
• "I apologize for any inconvenience this may have caused. I'll make sure to send the mail out ASAP."

Remember to be sincere and specific when apologizing. You could also offer a solution or a plan to make it right, such as "I'll send the letter out today" or "I'll make sure to get it to you by the end of the week."