[General] Email apologizes for the late reply.

[Aksinia]

Hello!

Please, tell me what's the best and accurate way to apologize for the late reply in formal letters?

I found some variants on the Internet. Here they are:
1) Sorry for being late in answering you.
2) Sorry for not replying sooner.
3) Sorry for not replying your letter.
4) Sorry for the long silence.
5) Please excuse my tardy reply to your letter.
6) Please forgive me for taking so long to reply.
7) I sincerely apologize for the delay in responce.
8) I apologize for the late responce to your email.
9) Apologizes for delay in replying to you.
10) My sencere apologizes foe delay in replying you.
11) My sencerest apologizes for the delayed responce.
I am confused...:?:

Thank you in advance.

 

[Rover_KE]

Please use the Edit Post feature to number your examples.

It will make it easier for us to refer to them individually.

 

[Rover_KE]

In a formal letter, I'd only use a full sentence, ruling out all but #5, 6, 7 and 8.

Note the correct spelling of 'response'.

My personal preference is for #6.

#9,10 and 11 have other serious spelling mistakes.