I followed your suggestion and added:
$email_message->SetBulkMail(1);
Now the junk mail error disappeared but the previous error returned.
This is the complete error:
Resolving POP3 authentication host "mail.schiu.com"...
Connecting to host address "*********" port 110...
S +OK Hello there.
C USER
[email protected]
S +OK Password required.
C PASS ********
S +OK logged in.
Resolving SMTP server domain "mail.schiu.com"...
Connecting to host address "*********" port 25...
Connected to SMTP server "mail.schiu.com".
S 451-The server has reached its limit for processing requests from your host.
Nao foi possível enviar o mail porque: it was not previously established a SMTP connection
Any other suggestion?
Thanks for your availability in answering my questions.