Inbound e-mail delay

Good Mornintg.

I am new to Cox services, and am seeking  information relative to processes that cause e-mail delays inbound.  My quest is to understand if this circumstance is something I must accept and adapt to for all emails.

Specifically the Following:

Received: from imap-backend-63.dovecot.iad.rs.oxcs.net (imap-backend-63.dovecot.iad.rs.oxcs.net [10.12.4.63])
        by mx.cox.rs.oxcs.net (Postfix) with ESMTP id 36214119B489
        for <g*******l.com>; Mon, 14 May 2018 13:30:55 +0000 (UTC)
X-Sieve: Pigeonhole Sieve 0.4.devel (404c208)
X-Sieve-Redirected-From: 3@6*****
Delivered-To: 3@6*****
Received: from imap-director-2.dovecot.iad.rs.oxcs.net ([10.12.2.9])
        by imap-backend-63.dovecot.iad.rs.oxcs.net with LMTP id WBrZCY+P+VojFwAA+uxsgg
        for <3@6*****3>; Mon, 14 May 2018 13:30:55 +0000

Received: from mx.cox.rs.oxcs.net ([10.12.2.9])
        by imap-director-2.dovecot.iad.rs.oxcs.net with LMTP id 0G6kCI+P+Vq5FgAAI4j0GA
        ; Mon, 14 May 2018 13:30:55 +0000

<<<< DELAY BETWEEN INTERNAL HOSTS >>>>>
Received: from eastrmimpi112.cox.net (unknown [68.230.240.52]) by mx.cox.rs.oxcs.net (Postfix) with ESMTP id 40l1WG4hjdz1DvXJ for <g*********et>; Mon, 14 May 2018 13:19:22 +0000 (UTC) Received: from sonic303-48.consmr.mail.ne1.yahoo.com ([66.163.188.174]) by eastrmimpi112.cox.net with cox id mDKL1x01s3mCCp601DKMYz; Mon, 14 May 2018 09:19:21 -0400

Which clearly illustrates the delay between 2 internal cox_labeled servers.

Is this the 'normal way' cox rolls, delay_wise?

Many Thanks