Solusi kirim email error : 554-us3.mx.mailhostbox.com ESMTP not accepting connections – dari cpanel

Siang ini saya menemukan ada client colocation yang tidak bisa kirim email ke email tujuan dengan error 554-us3.mx.mailhostbox.com ESMTP not accepting connections.

Untuk lengkap problem Log / Bounce back nya seperti berikut :

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  [email protected]
    host us3.mx1.mailhostbox.com [199.79.63.224]
    SMTP error from remote mail server after initial connection:
    554-us3.mx.mailhostbox.com ESMTP not accepting connections
    554 Please see http://support.mailhostbox.com/email-administrators-guide-error-codes/ for explanation of the problem.

Dan Jika di lihat dari log exim server nya seperti berikut :

2020-10-07 10:48:38 1kQ0RJ-0001eo-JP ** [email protected] <[email protected]> R=dkim_lookuphost T=dkim_remote_smtp H=us3.mx2.mailhostbox.com [199.79.63.226]: SMTP error from remote mail server after MAIL FROM:<[email protected]>: 550-5.7.1 Command rejected\n550 5.7.1 Please see http://support.mailhostbox.com/email-administrators-guide-error-codes/ for explanation of the problem.

Dari log di atas dapat disimpulkan kemungkinan IP mail out / IP smtp domain nya di blok oleh server tujuan .

Solusi nya :

• Cek dulu IP smtp / IP mail out domain anda di https://mxtoolbox.com/blacklists.aspx , apakah terblacklist RBL
• Coba ganti IP mail out / IP smtp domain anda
• Coba kirim ulang email nya ke tujuan , harus nya sudah bisa kirim email