Serious mail problems after updating iOS and Sierra

[gavroche]

Since updating iOS and Mac OS, i am having problems receiving emails. Normal emails seem to work fine... its SMTP emails that are generated by a server that are not coming through. They are taking as much as 4 hours to come through. This is affecting both a gmail account and a Yahoo account. My web host analyzed the headers for an email that came through 4 hours after it was sent.. and they told me that it had bounced around some relay servers.
I have changed no settings... any help?

 

[Tolien]

All email gets pushed around with SMTP and will typically go through a number of relays before their destination, so there's nothing unusual in what you've said.

Are these "server generated" emails going to both GMail and Yahoo from the same place (e.g., your web host)? It might help if you pasted the headers that your web host supposedly "analyzed".