ClosedRemote smtp server working slow

We have a droplet on digitalocean on frankfurt datacenter.
They have blocked mail server ports, so we have rent a remote mail hosting at turkish hosting company.
We are using remote smtp mail on opencart and it sends mail slow (5 seconds)
is it about the servers are far from each other or is there anything that i missed?

by the way, outlook sends and receive mails fast enough.

This is not an issue related to cyberpanel. Kindly contact digital ocean for support.