caroline rish wrote:

Yahoo user sometimes receives and sometimes does NOT receive my e-mails.
An answers out there.

Open an e-mail account somewhere OTHER than your current e-mail
provider. This is to eliminate internal routing when sending a test
e-mail to yourself that does not involve the boundary e-mail servers for
your e-mail provider. Send a test e-mail to the problematic recipient
and include yourself as a Bcc recipient to your other-domain account.
Then check if you receive your test e-mail at that other-domain account.
If you do then the problem is not on your end because you can see that
your outbound e-mail server did send out your test e-mail so the problem
is on the recipient's end where you have no control and the problem must
be addressed by the recipient.