Riguardo l'autenticazione SMTP il mio host mi dice
l'autenticazione sul server SMTP non garantisce l'invio corretto di una email ma serve solo per abilitare il servizio ad un indirizzo IP esterno.
Se il suo script risiede sul nostro server si presenta al server SMTP con l'indirizzo IP del webserver, pertanto non e' necessario effettuare l'autenticazione in quanto il server ha gia' abilitato tutta la classe IP per effettuare il relaying.
Detto questo se le e-mail le tornano indietro bisogna verificare la vera natura del problema e leggere attentamente il messaggio di errore che e' riportato nel notice della e-mail in questo modo si puo' capire la causa.
Ma allora serve o no questo PHPMailer? o cambio Host?


vai messaggi di errore
codice:
<---@hotmail.com>:
Connected to 65.55.92.184 but sender was rejected.
Remote host said: 550 OU-001 (SNT0-MC4-F7) Unfortunately, messages from 217.73.228.91 weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. 

<---@alice.it>:
Connected to 82.57.200.133 but sender was rejected.
Remote host said: 550 mail not accepted from blacklisted IP address [217.73.228.91]

<---@viabrenneroarchitettura.it>:
62.149.128.72 does not like recipient.
Remote host said: 553 Blocked by XBL http://www.spamhaus.org/query/bl?ip=217.73.228.91
Giving up on 62.149.128.72. 

<---@geaprogetti.it>:
Connected to 62.48.32.179 but greeting failed.
Remote host said: 554 5.7.1 Service unavailable; Client host [217.73.228.91] blocked using b.barracudacentral.org; http://www.barracudanetworks.com/rep...=217.73.228.91 

<---@tecsrl.eu>:
62.149.128.157 does not like recipient.
Remote host said: 553 Blocked by XBL http://www.spamhaus.org/query/bl?ip=217.73.228.91
Giving up on 62.149.128.157.

<---@tecnostudisrl.it>:
62.149.128.163 does not like recipient.
Remote host said: 553 Blocked by XBL http://www.spamhaus.org/query/bl?ip=217.73.228.91
Giving up on 62.149.128.163.

<---@libero.it>:
Connected to 212.52.84.70 but greeting failed.
Remote host said: 554 mtalibero28.libero.it

<---@calzedonia.it>:
Connected to 81.118.252.138 but greeting failed.
Remote host said: 554-mx1.calzedonia.com
554 Your access to this mail system has been rejected due to the sending MTA's poor reputation. If you believe that this failure is in error, please contact the intended recipient via alternate means.

<---@tin.it>:
Connected to 62.211.72.32 but sender was rejected.
Remote host said: 550 mail not accepted from blacklisted IP address [217.73.228.91]