Partial loss of emails from Sent folder

Just noticed this morning that - although I can view emails I Sent today -  all other emails dating back from 9/29/2016 to the present seem to have disappeared.  I do not recollect doing anything that may have caused this. 

This is a business account so the emails are doubly important to me.

Does anyone have an idea?

Hello Michael,
are those emails still accessible on your mail server? Or did this happen with a POP mail account?
Do you have Automatic Archiving enabled? (Menu>Tools>Settings>Mail>Automatic Archiving)
Do you have any backups of your database?

Regards,
Olivia

Olivia,

Thanks for your response. 

I found the Send emails hiding among the 1000s of others in the Trash.  I must have inadvertently erased them as a group at some point.

That won’t happen again! Thanks again, as well.

Mike

Hello Mike,
I am very glad to hear the messages were found.
Thank you for getting back to us with your solution.

Regards,
Olivia