not all my message have reply/forwards mark. how to all my message can have reply / forwards mark permanently? why the emails in inbox / sent item sometimes has striketrough?

Helloo...

i use windows live mail 2012 with IMAP, and OS windows 7

what i want to ask is..

1. necessarily, when we reply/forward a message from inbox, the reply/forward mark will appear in that message.

lately, i just realize not all my message have reply/forwards mark.

how to all my message can have reply / forwards mark permanently?

2. i am using IMAP as my incoming server.

sometimes when there is incoming email, not all my computer are getting the email.

example : my customer has sent me a message, in computer A, B, C, F, K, L has it, but in computer D, E ,G hasn't.

sometimes what we have to do is, move the message to inbox folder,,and taa dahhh the message appear

why did it happen?

3. and why the emails in inbox / sent item sometimes has striketrough?

and not all the computers did.

thanks

Op - reply's mark inbox disappeared