I have this domain, rimcostura.com, which is hosted by Netfirms. If you do a nslookup for the MX records it shows the right mail exchanger, this using opendns dns'. If I use other DNS' it also works fine.
I do send emails from gmail and yahoo and the recipient does get those emails.
But as soon as I try to send it from the web based mail system from Terra (terra.com.pe )
If I send and email to a none existent address (e.g. email@example.com) the server will send the email and then I'll get an email with a response stating the error message (either 550/554 gmail/yahoo).
If I send an email to XXX@rimcostura.com it fails immediately , it does not even send the email out and shows a popup windows with a none explanatory error saying that the recipient "probably" does not exist.
I'm sure it exists.
At one point this domain and the email was hosted by this company, so I'm pretty sure that there is a problem with a DNS server that did not update properly.
Call center is absolutely unresponsive, so I need to prove them that there is a problem at their end.
Any ideas on what test can I run to prove them wrong?