Email Devlivery issue

Hello
I am fetching some issues with email delivery.

This seems to be a continuing problem that users not receiving emails from MyWeb Application directly. It seems that addresses such as @msn.com, @comcast.net, @yahoo.com, @aol.com, etc. (@gmail.com does not seem to have any issues) commonly do not show my sent emails in their inbox and some private email domains also do not show our sent emails.

I am sending emails thought sendgrid. The from email is an @gmail.com address.