Error 503 Backend fetch failed

[Manuel A]

For three days ago configure attempt to send mail using SMTP through various plugins , through wordpress. With the first plugin I got USE send two test emails to different email addresses. since I could not send any more. I always get the answer:
Error 503 Backend fetch failed
Backend fetch failed

Guru Meditation:
XID: 29065639

Varnish cache server

Following the instructions of your page I have tried :
Clearing your browser cache
Disabling the cache

None of the above two solutions has solved my problem, which persists after three days. I have also tried to connect from other computers and the same problem persists.
Thanks in advance to anyone who can help me .

 

[Dead-i]

Hi,

We do not allow connections to external SMTP providers on our free hosting service, and our firewall automatically drops these connections. If you would like to send emails, please use the standard PHP mail() function to send an email from your hosting account.

Thank you,