Email Delivery Issues

Hi, I have a staff memeber who is trying to send email to someone outside the organisation, and they keep getting the below notification. They are trying to send to garyoh, but from the "ultimately generate by" part I am assuming there is a redirection or forward going on?

Also when I do an DNS, and MX lookup on mxtoolbox it says there are no A or MX records?? Their website is currently working and I can ping their hostname and it resolves an address.

Could it something on our end blocking the connection?

The address to which the message has not yet been delivered is:
(ultimately generated from
Delay reason: SMTP error from remote mail server after RCPT TO:<>:
host []: 451 4.3.0 <> Temporary user lookup failure
Josh RoweSystems AdministratorAsked:
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MASEE Solution Guide - Technical Dept HeadCommented:
You cannot send emaul to domain as there is no MX record .
Try to reach them by phone and make sure teh email address is correct.

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Josh RoweSystems AdministratorAuthor Commented:
Thanks for the info. I thought that was the case, but thought it wouldn't hurt to get someone else's eyes over it.
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