SMTP error

[ironcr35]

When ever I try to send an email I get this error,

SMTP error from remote mail server after RCPT TO:​

: host 198.91.80.251 [198.91.80.251]: 451 4.3.0 Error: queue file write error.

Thanks to anyone that can figure this out

 

[hbazer]

About 16:30 2013-03-14 UTC

I ran a Email test PHP script on the three (3) free-hosting servers and a Premium server [ s1 ]

The free-hosting servers would send mail to their self - where it was read - but not to any other Email server

The Premium server would send mail to its self - and to Email accounts on the three (3) free-hosting servers - and to a gmail.com Email account - where they were read

SMTP server for the three (3) free-hosting servers has a 'issue' with sending Emails to 'other' servers