Emails are not being saved, my sent mail folder

Hi everybody,
I am using a new Apple MacBook Pro ME864LL/A.
Sometimes my internet connection is very poor. That time I can't even connect to the internet. Today I sent one important professional email. It was received by the receiver. But due to poor connection, it didn't get saved in my sent mail folder. So that email was lost in my system.
How can I solve this issue? Anybody faced the same issue? Please suggest me something to resolve this. Thanks!
