Knowledge Base

Incoming

Using telnet you can manually test if the destination server is correctly accepting the email. To do so, you have to lookup the destination route in the SpamExperts Control Panel set for a domain, and try delivery:

demo1.spambrand.com:~$ telnet destinationserver 25
Trying x.x.x.x...
Connected to destinationserver.
Escape character is '^]'. 220 destinationserver ESMTP
helo demo1.spambrand.com
250 destinationserver at your service
mail from:<>
250 2.1.0 OK
rcpt to: user@domain.tld
250 2.1.5 OK
quit
221 2.0.0 closing connection Connection closed by foreign host. demo1.spambrand.com:~$

Please note that for the recipient callout we always use an empty “mail from:<>”

cPanel

Please make sure that when manually changing your domain MX records, the cPanel Email Routing settings are always set to “Local Mail Exchanger” instead of “Automatically Detect Configuration”. Otherwise the cPanel server will reject all email to this domain, this will show in the log search as “Recipient Rejected by destination server”. Since it is a permanent reject at the destination server, the mail will be permanently rejected. Permanent failures, including failed Recipient Callouts, are being cached up to two hours.

Outgoing
Using telnet you can manually test if a destination domain is correctly accepting the email. To do so, you have to lookup the destination MX record of the domain, and try a delivery:

demo1.spambrand.com:~$ host destinationdomain
destinationdomain has address x.x.x.x
destinationdomain mail is handled by 10 destinationserver.
demo1.spambrand.com:~$ telnet destinationserver 25
Trying x.x.x.x...
Connected to destinationserver.
Escape character is '^]'.
220 destinationserver ESMTP
helo demo1.spambrand.com
250 destinationserver at your service
mail from: <>
250 2.1.0 OK
rcpt to:
250 2.1.5 OK
quit
221 2.0.0 closing connection Connection closed by foreign host. demo1.spambrand.com:~$

This entry was posted on Thursday, November 29th, 2018 at 12:00 pm and is filed under Antispam Cloud.