Gmail SENT MAIL Confusion

[MamasBoy]

About a year ago I began to have problems with my Gmail and to this day they remain unresolved. (ASUS desktop with Windows 8.1)
Specifically, when I send a Gmail, I used to see the email in SentMail, but now I get a message that says something abut a trashed conversation and it doesn't automatically go to SentMail.

[4wd]

It might help if you told us how you access your Gmail account, ie. via an email client using IMAP/POP or via the web interface in a browser.
And precisely which Sent Mail folder you're talking about, ie. the one on Google's servers or the one in an email client.